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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.
121

Expression of Growth Arrest and DNA Damage Protein 45-alpha (gadd45-alpha) and the CCAAT/enhancer binding protein-delta (C/EBP-delta) in Fishes Exposed to Heat and Hypoxia

Hassumani, Daniel Omar 20 March 2013 (has links)
The cellular stress response (CSR) is one of the most highly conserved mechanisms among all organisms. Cellular stress can be defined as damage or the threat of damage to proteins, macromolecules and/or DNA. The response to damage can involve cell cycle regulation, protein chaperoning, DNA repair or, if macromolecular damage is too severe, apoptotic mechanisms can be initiated. This thesis details experiments that were designed to examine the cellular response to non-lethal environmental stressors at the protein level, using two fish species as study models. Two proteins that can cause cell cycle arrest and apoptosis mechanisms were examined. Expression of the CCAAT enhancer binding protein-delta (C/EBP-[delta]) was examined in the zebrafish, Danio rerio, exposed to acute, non-lethal hypoxic conditions. While C/EBP-[delta] was expressed constitutively in control individuals during all time points, exposure to hypoxic conditions did not have a consistent significant effect on C/EBP-[delta] expression (two-way ANOVA, P>0.05) in zebrafish white muscle tissue. In a second study, the expression of the growth arrest and DNA damage 45-alpha protein (gadd45-[alpha], a mediator of cell cycle arrest and perhaps apoptosis was examined in heat-stressed liver tissue of an extremely cold-adapted Antarctic fish, Trematomus bernacchii. Gadd45-[alpha] levels were higher in fish exposure to 2°C across all time points (one-way ANOVA; P
122

Characterization of ABF-1 in C. elegans and regulation of cellular growth and ID3 by human ABF-1

Round, June L. 01 January 2002 (has links)
ABF -1 is a human class II bHLH transcription factor that is expressed predominantly in activated B cells and EBV immortalized cell lines. A portion of this study sought to characterize the homolog of ABF- l in Caenorhabditis e/egans. The nematode gene product, ceABF -1, is capable of forming heterodimers with E2A gene products and binding E box binding sites. HeLa cells transfected with ceABF-1 reveal that it is capable of blocking E2A mediated gene transcription. In order to maintain full repression capabilities, two conserved amino acid residues within helix I ofthe HLH domain are required. These results show a conserved mechanism of gene repression between invertebrates and vertebrates. This study also sought to analyze ABF-1 mediated regulation of both ld3 and cellular growth. Using a human ABF-1 stably transfected cell line, ID3 protein levels and transcript levels were shown to increase in response to overexpression of ABF-1 via western and northern blot, respectively. Flow cytometry analysis and Real-time PCR revealed that ABF-1 programs a slow down in the cell cycle, however this growth arrest is not mediated by ID3.
123

Characterization of Avian TLR3 Gene: Alternative Splicing and Cleavage Activity on Its Ectodomain

K C, Mahesh 10 August 2017 (has links)
No description available.
124

Biomechanical control mechanisms and morphology for locomotion in challenging scenarios

Pfeiffenberger, Janne Akseli January 2017 (has links)
Everyday ecologically relevant tasks that affect organismal fitness, such as foraging, reproduction, predator avoidance, and escape responses, rely upon successful locomotion. The effectiveness of animal locomotion depends on many underlying factors, such as the morphology of the locomotor limbs, which evolved to fulfill specific locomotor tasks. Besides morphology, the material properties of the limbs also play a crucial role in locomotion. The skeletal structures of locomotor limbs must be able to withstand the repeated stresses that come with locomotion, either on land or underwater, as they use their limbs to generate propulsive forces. The natural environment animals move in is complex and dynamic, as various conditions crucial to locomotor performance can change unexpectedly. Perturbations to locomotor stability can take different forms, such as elevation changes, obstacles, substrate changes, and slipping. To maintain stable locomotor performance in these environments, animals rely on locomotor control mechanisms to counteract destabilizing effects of locomotor perturbations. In this Dissertation, I investigated the biomechanical control mechanisms and morphological adaptations during locomotion in challenging locomotor scenarios. Over the course of three chapters, the goals were to: 1) explore the effects of limb loss on a side-ways running sprint specialist, the Atlantic ghost crab, 2) determine the response and control mechanisms that allow ghost crabs overcome slip perturbations, and 3) to describe the pelvic morphology of bottom-walking Antarctic plunderfish and compare the pelvic morphologies among multiple species of nothenioids that do not bottom-walk. This study demonstrates the robustness of Atlantic ghost crabs to limb loss and slip perturbations. Paired limb removals resulted in a pattern of kinematic adjustments, which reduced locomotor performance by up to 25%, which was dependent on specific limbs being lost. I suggest that these limbs serve more important limb functions that can’t be replaced by the remaining limbs, however the loss of these particular limbs also results in re-patterning of limb relationships, which may reveal a neural component that may be the cause of decreased locomotor performance. Slip perturbations on the other hand were found to not have any significant effects on the locomotor performance of ghost crabs. Kinematics remained constant as ghost crabs traversed the slip surface, suggesting that ghost crabs may rely on feedforward control to overcome slip perturbations, however further studies measuring neural activity are required to confirm our finding. Most importantly though this chapter demonstrates and corroborates the role of momentum and how it allows animals to overcome perturbations. The last chapter investigated the pelvic morphology and material properties of fin rays in bottom walking fish. The Antarctic plunderfish was found to possess high flexural stiffness in its pelvic fin rays, which likely facilitate the bottom walking behavior in this species. Other, non-bottom walking notothenioids did not have fin rays of similar stiffness. Pelvic plate morphology was not different between species, however there were stark differences in mineralization. The bottom-walking fish had higher bone mineral density compared to the other species analyzed in this chapter. I also found mineralization patterns which seem to align with muscle fiber alignment of the major pelvic muscles, suggesting that these regionalized increases in stiffness provide stability while allowing for a lightweight pelvic plate. / Biology
125

Contracting Out in a Complex Network: An Effectiveness Analysis of EPC Program I

Moussa, Edie A. 27 June 2011 (has links)
While government contracting out its work continues to proliferate and studies about this phenomenon have increased during the past two decades, still little is known about how effective government sponsored networks are at managing broad and complex networks of primarily non-governmental entities. This dissertation reports the results of one such investigation, which examined a U.S. federal agency's contracting experiences in evidence-based health care. The Agency for Healthcare Research and Quality (AHRQ) is a unit of the U.S. Department of Health and Human Services (HHS). Among other tasks, AHRQ supports the development and dissemination of evidence about current best practices in health services delivery through its Evidence-based Practice Center (EPC) programs that contract out its work and operate in broad and complex network. The purpose of this study was to examine the extent to which AHRQ's EPC Program I was effective in supporting the translation of evidence reports and disseminating the products to the public by contracting with public and non-profit entities to do the work. This dissertation also sought to examine the extent to which the evidence reports and derivative products were publicly accessible by operationalizing the objectives articulated in AHRQ's authorizing legislation in a manner consistent with theories of representative democracy and exploring Program I's effectiveness using William T. Gormley's ideas (1989; Gormley & Balla 2003) of bureaucratic control. The results from this dissertation suggest that a decentralized network was related to overall higher translation and dissemination network effectiveness. Specifically, the findings from this study suggest that a decentralized network was related to overall higher translation and dissemination network effectiveness. Also, weak ties among the network actors when transferring complex knowledge was associated with higher translation and dissemination network effectiveness on the whole. The findings from this dissertation also contribute to network theory by extending Gormley's bureaucratic control typology (1989; Gormley & Balla 2003) to the network level, and also to the type of control that was available to the Agency over the network. Finally, the results contribute to better understanding of the dynamics that can be associated with the effectiveness of similar programs. / Ph. D.
126

Developmental and Protective Mechanisms of the Ocular Lens.

Unknown Date (has links)
The vertebrate eye lens functions to focus light onto the retina to produce vision. The lens is composed of an anterior monolayer of cuboidal epithelial cells that overlie a core of organelle free fiber cells. The lens develops and grows throughout life by the successive layering of lens fiber cells via their differentiation from lens epithelial cells. Lens developmental defect and damage to the lens are associated with cataract formation, an opacity of the lens that is a leading cause of visual impairment worldwide. The only treatment to date for cataract is by surgery. Elucidating those molecules and mechanisms that regulate the development and lifelong protection of the lens is critical toward the development of future therapies to prevent or treat cataract. To determine those molecules and mechanisms that may be important for these lens requirements we employed high-throughput RNA sequencing of microdissected differentiation statespecific lens cells to identify an extensive range of transcripts encoding proteins expressed by these functionally distinct cell types. Using this data, we identified differentiation state-specific molecules that regulate mitochondrial populations between lens epithelial cells that require the maintenance of a functional population of mitochondria and lens fiber cells that must eliminate their mitochondria for their maturation. In addition, we discovered a novel mechanism for how lens epithelial cells clear apoptotic cell debris that could arise from damage to the lens and found that UVlight likely compromises this system. Moreover, the data herein provide a framework to determine novel lens cell differentiation state-specific mechanisms. Future studies are required to determine the requirements of the identified molecules and mechanisms during lens development, lens defense against damage, and cataract formation. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
127

Highwire's characterization and signaling roles in Drosophila central synapse formation

Unknown Date (has links)
The assembly and maintenance of central synapses is a complex process, requiring myriad genes and their products. Highwire is a large gene containing a RING domain, characteristic of ubiquitin E3 ligases. Highwire has been shown to restrain axon growth and control synaptogenesis at a peripheral synapse. Here I examine the roles of Highwire at a central synapse in the adult Drosophila Giant Fiber System (GFS). Highwire is indeed necessary for proper axonal growth as well as synaptic transmission in the GFS. Differences arise between the central synapse and the neuromuscular junction (NMJ), where highwire was initially characterized : expresion from the postsynaptic cell can rescue highwire synaptic defects, which is not seen at the NMJ. In addition, a MAP kinase signaling pathway regulated by highwire at the NMJ has differing roles at a central synapse. Wallenda MAPK can rescue not only the highwire anatomical phenotype but also the defects seen in transmission. Another distinction is seen here : loss of function basket and Dfos enhance the highwire anatomical phenotype while expression of dominant negative basket and Dfos suppress the highwire phenotype. As a result we have compared the signaling pathway in flies and worms and found that the NMJ in the two organisms use a parallel pathway while the central synapse uses a distinct pathway. / by Kimberly Diane Rowland. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.
128

Hippocampal CA1 activation during object memory encoding in the novel object recognition task

Unknown Date (has links)
Transcription and translation of proteins are required for the consolidation of episodic memory. Arc, an effector immediate early gene, has been linked to synaptic plasticity following learning and memory. It is well established that the rodent hippocampus is essential for processing spatial memory, but its role in processing object memory is a point of contention. Using immunohistochemical techniques, hippocampal sections were stained for arc proteins in the CA1 region of the dorsal hippocampus in mice following two variations of the novel object recognition (NOR) task. Results suggest mice that acquired strong object memory showed significant hippocampal activation. In mice that acquired weak object memory, hippocampal activation was not significantly different from controls. Arc expression was also examined in other hippocampal sub-regions, as well as in the perirhinal cortex. These results suggest that the mice must acquire a threshold amount of object information before the hippocampal CA1 region is engaged. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection
129

Critérios de identificação e controle das normas tributárias extrafiscais

Detzel, Aline Martinez Hinterlang de Barros 06 November 2018 (has links)
Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2018-12-12T09:24:08Z No. of bitstreams: 1 Aline Martinez Hinterlang de Barros Detzel.pdf: 957775 bytes, checksum: d2e7fb9ddd0c2b7e17e5ec213db37525 (MD5) / Made available in DSpace on 2018-12-12T09:24:08Z (GMT). No. of bitstreams: 1 Aline Martinez Hinterlang de Barros Detzel.pdf: 957775 bytes, checksum: d2e7fb9ddd0c2b7e17e5ec213db37525 (MD5) Previous issue date: 2018-11-06 / It is an incontrovertible fact that extrafiscality, a legal instrument legitimized for the purpose of pursuing certain constitutionally defined goals, has grown exponentially. The common option of the competent agents regarding the use of this legal instrument demands a deeper analysis on the structuring aspects of extra-fiscal tax. In this context, the identification of possible structuring rules of extra-fiscal tax becomes urgent, thus facilitating the application of certain legal control mechanisms. The theme of extrafiscality, as presented in this study, demands the overcoming of some of the positions adopted by Brazilian tax doctrine. With this, it is intended to add to the topic legal aspects of great importance to the Tax Law, which contribute to the structuring and maintenance of a more efficient and secure constitutional tax system, from the point of view of the individual guarantees of the taxpayers / É fato incontroverso que a extrafiscalidade, instrumento jurídico legitimado para fins da persecução de determinados objetivos constitucionalmente definidos, tem crescido de forma exponencial. A corriqueira opção dos entes competentes quanto à utilização deste instrumento jurídico demanda uma análise mais profunda acerca dos aspectos estruturantes das normas tributárias extrafiscais. Neste contexto, a identificação dos possíveis critérios estruturantes das normas tributárias extrafiscais se torna premente, facilitando, por conseguinte, a aplicação de determinados mecanismos jurídicos de controle. A temática da extrafiscalidade, tal qual apresentada neste trabalho, demanda a superação de alguns posicionamentos majoritariamente adotados pela doutrina tributária brasileira. Com isso, pretende-se agregar ao tema aspectos jurídicos de grande importância para o Direito Tributário, os quais contribuem para a estruturação e manutenção de um sistema constitucional tributário mais eficiente e seguro, sob o ponto de vista das garantias individuais dos contribuintes
130

Creative Control : How to Manage Innovation and New Product Development

Haapanen, Heta-Liisa, Kaukonen, Ulla January 2010 (has links)
<p>The topic of this research is to explore to what extent innovation and new product development (NPD) are managed with formal and informal control mechanisms respectively and in combination in five international food industry companies. The topic deals with finding an understanding of controlling innovation processes which require freedom to some extent but at the same time are to be managed in order to keep track of the resources. Cases’ selection was designed to bring variation and catch the complexity of the phenomenon by studying one prime case and validating the results with four minor case companies’ results. The findings of the study indicate that first of all formal and informal control mechanisms coexist and interact and secondly that a more informal and personalized take is beneficial in R&D settings.</p>

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