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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

The Safety, Tolerability, and Efficacy of Electrical Nerve Stimulation on Physiological Activity and Golf Performance

January 2020 (has links)
abstract: Electrical nerve stimulation is a promising drug-free technology that could treat a variety of ailments and disorders. Methods like Vagus Nerve Stimulation have been used for decades to treat disorders like epilepsy, and research with non-invasive vagus nerve stimulation has shown similar effects as its invasive counterpart. Non-invasive nerve stimulation methods like vagus nerve stimulation could help millions of people treat and manage various disorders. This study observed the effects of three different non-invasive nerve stimulation paradigms in human participants. The first study analyzed the safety and efficacy of transcutaneous auricular vagal nerve stimulation in healthy humans using a bilateral stimulation protocol with uniquely designed dry-hydrogel electrodes. Results demonstrate bilateral auricular vagal nerve stimulation has significant effects on specific parameters of autonomic activity and is safe and well tolerated. The second study analyzed the effects of non-invasive electrical stimulation of a region on the side of the neck that contains the Great Auricular Nerve and the Auricular Branch of the Vagus Nerve called the tympanomastoid fissure on golf hitting performance in healthy golfers. Results did not show significant effects on hitting performance or physiological activity, but the nerve stimulation had significant effects on reducing state-anxiety and improving the quality of feel of each shot. The third study analyzed the effects of non-invasive nerve stimulation of cervical nerves on the back of the neck on putting performance of yips-affected golfers. Results demonstrated that cervical nerve stimulation had significant effects on improving putting performance but did not have significant effects on physiological activity. Data from these studies show there are potential applications for non-invasive electrical nerve stimulation for healthy and athletic populations. Future research should also examine the effects of these stimulation methods in clinical populations. / Dissertation/Thesis / Doctoral Dissertation Biomedical Engineering 2020
372

Uncovering Pathways Regulating ILC Metastasis Through miRNA Expression Analysis and Generation of Novel Invasive ILC Models

Allen, Victoria 13 September 2019 (has links)
Invasive lobular carcinoma (ILC) is the second most common form of breast cancer. ILC presents at later stages with many challenges, therefore improved diagnostic and therapeutic targets are needed. A microRNA (miRNA) genome analysis identified miR-23c and miR-23b-3p as possible regulators of ILC invasion due to their significantly increased expression in invasive compared to minimally invasive ILC cell lines. By decreasing the levels of miR-23c and miR-23b-3p using hairpin inhibitors, the invasive MDA-MB-330 cell line had significantly reduced invasion, while overexpressing these miRNAs using mimics in the minimally invasive MDA-MB-134VI cell line increased invasion. During the course of this study, it became apparent that limited tools exist for studying invasive ILC. Therefore, two more invasive ILC cell line models were created by isolating and expanding MDA-MB-134VI cells that had invaded through Matrigel® coated invasion chambers. This thesis has thus created new models of invasive ILC as well as identified miR-23c and miR-23b-3p as regulators of MDA-MB-330 and MDA-MB-134VI cell line invasion.
373

A Model Explaining Medusahead Invasion and Novel Targeted Grazing Approaches of Control

Spackman, Casey N. 01 December 2019 (has links)
Medusahead (Taeniatherum caput-medusae (L.) Nevski) is currently one of the biggest threats to rangelands and livestock operations in the Western US. High silica concentrations in medusahead contribute to its invasiveness. I developed a model to explain how silica is involved in the invasion process, and attempted to manipulate silica to increase use of the grass by livestock. Experiments were conducted to determine: 1) whether rotational grazing on established forages of improved nutritional quality would provide supplemental nutrients to increase cattle use of medusahead; 2) evaluate intake of and preference for medusahead treated with a glyphosate herbicide at different rates by sheep; and 3) evaluate intake and selection of medusahead by cattle by separating the effects of a glyphosate herbicide (Roundup®) from other chemicals in the formulation (salt, adjuvant). Additionally, experiments were conducted to 4) determine the nutritional value and digestibility of medusahead treated with Roundup® at different rates and at different plant particle sizes; and 5) determine if cattle grazing with trampling can increase seeding success on medusahead-invaded rangelands. Rotational grazing from supplemental pastures to medusahead-invaded pastures increased medusahead use by cattle during the second year of the study. Furthermore, glyphosate did not increase medusahead consumption in a choice between three glyphosate treatments, but did in a two-way choice test. Cattle grazed glyphosate-treated medusahead more than that of the non-treated grass and completely avoided the salt-treated grass. The active ingredient in a glyphosate herbicide increased consumption of medusahead while other ingredients in the herbicide (i.e., salt and adjuvant) had no influence on this choice. A smaller particle size increased the digestibility of medusahead compared to larger particle sizes. Glyphosate also increases digestibility, but not as much as particle size. Finally, cattle trampling did not help establish seeded plant species, and the seeding attempt was unsuccessful. Thus, grazing rotations between improved pastures and medusahead-infested rangeland, and the combined glyphosate application-grazing are new approaches for medusahead control, as they prepare a seed bed for revegetation and increase the nutritional quality of the grass for improved livestock nutrition.
374

The effect of temperature on the interaction between larvae of a native and a range expanding dragonfly species

Everling, Sanne January 2021 (has links)
Climate change might affect the distribution of species; therefore, it is important to anticipate the imminent impact of climate change. Even though climate responses have the potential to affect species interactions, most models on the effect of climate change on species distribution assume that species respond to climate individually. Hence studies on competition effects are needed. In this study, I estimated growth, mortality, and behaviour (prey capture success, activity, exploration and boldness) at 20° C and 23° C at intra- and interspecific competition conditions in larvae of a native and a northward dispersing dragonfly. The results showed that the northward expanding Sympetrum fonscolombii had a higher growth and survival rate compared to the native Sympetrum vulgatum at interspecific conditions. At intraspecific conditions the results showed that temperature had no significant effect on the performance of S. fonscolombii, but S. vulgatum showed both a higher growth rate and a higher mortality at 23 ° C. A significant difference between temperatures within prey capture success rate was found in S. vulgatum only, during the second observation period. There was a correlation between activity and exploration in both species, between prey capture success rate and activity during the third observation round in S. vulgatum, and between prey capture success rate and boldness during the first observation round in S. fonscolombii. No other behaviours were correlated. Prey capture success rate was shown to be repeatable in both species, while boldness was repeatable in S. vulgatum only. The behavioural results suggests that behavioural traits are relatively plastic over ontogeny in both species, possibly caused by behavioural variation within each instar. Additionally, boldness, but not activity and exploration, might aid S. fonscolombii in their northward expansion. The majority of these results were similar at both temperatures and indicate that S. fonscolombii has a higher capacity to tolerate climate change, and their presence might negatively impact the performance of S. vulgatum.
375

GIS-Based Rapid-Assessment of Bighead carp Hypophthalmichthys nobilis (Richardson, 1845) Suitability in Reservoirs

Long, James M., Liang, Yu, Shoup, Daniel E., Dzialowski, Andrew R., Bidwell, Joseph R. 01 January 2014 (has links)
Broad-scale niche models are good for examining the potential for invasive species occurrences, but can fall short in providing managers with site-specific locations for monitoring. Using Oklahoma as an example, where invasive bighead carp (Hypophthalmichthys nobilis) are established in certain reservoirs, but predicted to be widely distributed based on broad-scale niche models, we cast bighead carp reproductive ecology in a site-specific geospatial framework to determine their potential establishment in additional reservoirs. Because bighead carp require large, long free-flowing rivers with suitable hydrology for reproduction but can persist in reservoirs, we considered reservoir tributaries with mean annual daily discharge ≥8.5 cubic meters per second (m3/s) and quantified the length of their unimpeded portions. In contrast to published broad-scale niche models that identified nearly the entire state as susceptible to invasion, our site-specific models showed that few reservoirs in Oklahoma (N = 9) were suitable for bighead carp establishment. Moreover, this method was rapid and identified sites that could be prioritized for increased study or scrutiny. Our results highlight the importance of considering the environmental characteristics of individual sites, which is often the level at which management efforts are implemented when assessing susceptibility to invasion.
376

Recurrent Invasive Lobular Carcinoma Presenting as a Ruptured Breast Implant

Botros, Maikel, Chang, Kenneth, Miller, Robert, Krishnan, Sunil, Iott, Matthew 01 March 2012 (has links)
Background. For years, the treatment for invasive lobular carcinoma (ILC) has been mastectomy secondary to the lack of studies investigating the efficacy of breast conservation therapy on patients afflicted with ILC and due to the lack of long-term follow up investigating locoregional recurrence in this patient population. In this article we report the clinical course of a patient diagnosed with ILC. Case report. We describe the case of a 50-year-old woman with stage IIB (T2N1M0) ER/PR positive right breast ILC who underwent a right modified radical mastectomy, postoperative chemotherapy, a prophylactic left simple mastectomy with bilateral breast reconstruction and tamoxifen. Approximately 12 years later, she presented with a deflated breast implant and recurrent breast cancer with metastatic spread. She received palliative radiotherapy then palliative chemotherapy. Unfortunately, she succumbed to the cancer less than a year after being diagnosed with metastatic disease. Conclusions. This may be the first case report of a ruptured breast implant presenting at the same time as the diagnosis of recurrent breast cancer.
377

INVASIVE PLANTS AND NATIVE AMPHIBIANS: THE IMPLICATIONS FOR AMPHIBIAN CONSERVATION IN EASTERN NORTH AMERICA

Regula, Lis Kenneth 06 December 2013 (has links)
No description available.
378

Mycorrhizae In Sagebrush-Steppe Community Restoration: Mycorrhizal Dependency Of Invasive And Native Grasses With Intraspecific And Interspecific Competition

Scherpenisse, Dara S. 01 May 2009 (has links)
Mycorrhizae have been used in restoration for decades. However, studies assessing the use of mycorrhizae in Bromus tectorum-invaded areas of the Great Basin are limited. Two greenhouse pot experiments were conducted to assess the role of mycorrhizae in sagebrush restoration. The first objective (Chapter 2) was to determine the response of Pseudoroegneria spicatum, Elymus elymoides, and B. tectorum to mycorrhizal symbiosis by altering phosphorus, density, species, presence of mycorrhizae and water levels in a 5 factor design. To assess the mycorrhizal response, a variety of morphological and physiological traits were measured, such as tissue P concentration, specific root length, specific leaf area, carbon isotope discrimination, etc. The effects of the different treatment combinations were analyzed using ANOVA. The second objective (Chapter 3) was to determine the role of different inocula in competition between the three grasses. Species, density, and inoculum type were altered in a 3 factor design. Inoculum was cultured on Allium plants. The effect of locally cultured inoculum on the species was compared to the effect of commercial inoculum. The response of each species to mycorrhizae with different species compositions and densities was assessed. Morphological measurements were used to determine each species response to the different factor combinations. The effects of the different treatment combinations were analyzed using ANOVA. This research provides land managers with information regarding the efficacy of using local versus commercial inocula and whether they should use mycorrhizae in restoring their systems.
379

Impacts of <i>Phragmites australis</i> Management on Wetland Plant Community Recovery, Seedbank Composition, and the Physical Environment in the Chesapeake Bay

Hazelton, Eric L. G. 01 August 2018 (has links)
Biological invasions have adverse economic, cultural, and ecological effects worldwide. Among the most impactful in North America is the invasion of Phragmites australis (Phragmites), a large-scale clonal grass that rapidly colonizes wetlands. Phragmites crowds out native plants and alters habitat for native fauna. In doing so, Phragmites also alters human access to water resources and has adverse economic effects, including decreasing property value, inhibiting recreational use, and limiting populations of game species. The efforts described in this dissertation are a component of a large, multidisciplinary effort to better understand the anthropogenic stressors to Chesapeake Bay, Maryland, at the land/water interface. Utah State University worked in collaboration with the Smithsonian Environmental Research Center and other academic and public organizations to address this problem from multiple directions. The diverse and extensive studies ranged from aquatic and avian faunal composition and submerged aquatic vegetation to our work on the invasive wetland grass, Phragmites. Having assessed the existing literature and its shortcomings, we conducted a large-scale, long-term study of the effects of Phragmites removal on the Bay. By removing Phragmites from plots in select sub-estuaries of Chesapeake Bay through herbicide spraying, leaving associated plots intact, and comparing both with native wetland conditions, we sought to better understand herbicidal management of Phragmites and the potential for wetland plant community recovery. Although sprayings decreased the relative cover, stem diameters, and stem densities of Phragmites, we found that herbicide treatment alone was not adequate to restore native plant communities or significantly affect seedbank composition. Our results demonstrate the resilience of Phragmites and call for a diverse range of control measures, including mowing, grazing, burning to expose the seedbank to germination, and—if economics allow—active revegetation to establish the desired plant community composition. This dissertation provides beneficial data for those who seek to manage Phragmites in wetland plant communities, but there is much work still to be done. The literature review, seedbank study, and community analysis included in this volume are components of a larger research program on Phragmites management. Future studies should, in particular, investigate revegetation and nutrient amelioration as means to recover pre-invasion vegetation.
380

The Role of an Invasive Exotic Plant on the Structure of Aquatic Invertebrate Assemblages: Tamarix in the Southwest United States

Lewis, Bert 01 May 1998 (has links)
Over the past 100 years, riparian vegetation communities throughout the Southwest United States have been extensively invaded by Tamara spp. (saltcedar). Saltcedar derives its common name from its physiological adaptation to excrete salts. The production of Tamarix detritus with associated secondary chemicals may affect the quality of aquatic invertebrate food and habitat resources. An alteration in food and habitat quality may affect the composition and structure of aquatic invertebrate assemblages. A series of experiments was conducted contrasting aquatic invertebrate assemblage densities, colonization rates, and growth rates associated with Tamarix versus native vegetation, Populus fremontii (cottonwood) and Salix exigua (willow), to determine if aquatic invertebrate assemblages have been altered by the invasion of Tamarix. Results of invertebrate growth rates over 13 weeks indicate that Tamarix is minimally different in food quality to cottonwood and willow. I failed to find differences in invertebrate colonization rates or invertebrate assemblage densities associated with Tamarix compared to cottonwood and willow over two 6-week time periods.

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