Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Entire DC Network

Beyond Cortisol: Indicators Of Stress And Negative Feedback In Plasma And Blubber Of Marine Mammals, Jessica Avalos Jan 2022

Beyond Cortisol: Indicators Of Stress And Negative Feedback In Plasma And Blubber Of Marine Mammals, Jessica Avalos

University of the Pacific Theses and Dissertations

Marine mammals play an important role in ecosystem stability. However, anthropogenic activity is compounding pressure on many already vulnerable populations. A potential consequence of anthropogenic disturbance is physiological stress, which can impact metabolism, immunity, and reproduction, especially if it occurs repeatedly. Previous studies on marine mammals have focused on acute stress, but the impacts of repeated stress are poorly understood. Due to its accessibility on land during haul-outs, the northern elephant seal (Mirounga angustirostris) is a good system in which to study the effects of stress in marine mammals. Stress stimulates the release of glucocorticoid hormones, primarily cortisol. Elevated cortisol …


Inhibition Of Staphylococcus Aureus Biofilm By Variovorax Paradoxus, Esther Gomez Jan 2022

Inhibition Of Staphylococcus Aureus Biofilm By Variovorax Paradoxus, Esther Gomez

University of the Pacific Theses and Dissertations

Staphylococcus aureus is one of the leading causes of fatal nosocomial infections. Often, S. aureus can grow as a biofilm which protects the population from the surrounding environment. Strains of S. aureus are resistant to virtually all known antibiotics on the market. Variovorax paradoxus is a soil microbe with many unusual metabolic activities. It has been previously observed that, V. paradoxus can inhibit the growth of S. aureus when in co-culture. In this work we report on inhibition of S. aureus biofilm formation by V. paradoxus due to a suspected inhibitory soluble factor.


Impacts Of Plastic Pollution On A Pelagic Marine Mammal, The Northern Elephant Seal, Lauren M. Kashiwabara Jan 2022

Impacts Of Plastic Pollution On A Pelagic Marine Mammal, The Northern Elephant Seal, Lauren M. Kashiwabara

University of the Pacific Theses and Dissertations

As plastic pollution increases, top marine predators such as marine mammals are becoming increasingly susceptible to plastic particles and their additives. Plastic particles have been found in gastrointestinal tracts and scat of many marine mammals, and quantifying plastic pollution in those that are pelagic can provide insight into plastic pollution in mesopelagic ecosystems that are just beginning to be analyzed. Adapting well-developed laboratory techniques for microplastic (MP) isolation (i.e. density separation and chemical digestion), I isolated MPs from the scat of the deepest diving pinniped, the northern elephant seal (NES), and found that100% of scat samples (n=11) contained high counts …


Cpf1-Based Crispr Genome Editing In The Cyanobacterium N. Punctiforme, Soohan Woo Jan 2022

Cpf1-Based Crispr Genome Editing In The Cyanobacterium N. Punctiforme, Soohan Woo

University of the Pacific Theses and Dissertations

CRISPR systems have been growing in their utility and their application throughout the biological field as researchers continue to grow in their understanding of the relatively novel genome editing technology. However, despite the potential of CRISPR as a genome editing tool, the complexity of applying this technology to a specific organism calls for custom modifications to the system to improve its success rate. In this project, a CRISPR-Cpf1 system that can be effectively employed in the cyanobacterium Nostoc punctiforme was designed, with a focus on the hormogonium development of this species. Multiple plasmids containing the CRISPR system and targeting different …


Regulation Of Ppp1r15a (Gadd34) And Ppp1r15b (Crep) Mrna Expression And Localization In The Unfolded Protein Response, Krithika Giresh Jan 2022

Regulation Of Ppp1r15a (Gadd34) And Ppp1r15b (Crep) Mrna Expression And Localization In The Unfolded Protein Response, Krithika Giresh

University of the Pacific Theses and Dissertations

The failure to balance protein synthesis, folding, and degradation in the endoplasmic reticulum (ER) leads to the accumulation of unfolded proteins, leading to ER stress. Cells respond to this stress by activating a response signaling pathway known as the Unfolded Protein Response (UPR). One of the branches of the UPR induces the phosphorylation of eIF2α (Eukaryotic Initiation Factor 2) to attenuate global protein synthesis, allowing for a chance to clear misfolded and unfolded proteins. This phosphorylation of eIF2α is opposed by a phosphatase, containing a catalytic subunit, Protein Phosphatase 1, and a scaffolding protein, either GADD34 or CReP. Inhibition of …


Land-Use And Ant Biodiversity In California’S Central Valley, Laura L. Navarro Jan 2022

Land-Use And Ant Biodiversity In California’S Central Valley, Laura L. Navarro

University of the Pacific Theses and Dissertations

The growing human population results in growing demand for land allocated to urban development and agricultural production (Godfray et al. 2010; Tilman et al. 2011; McDonnell and Hahs 2013; Alexander et al. 2015; Erlwein and Pauleit 2021). Changes to land allocation associated with agricultural and urban development will increasingly alter terrestrial ecosystems impacting biodiversity (Ricketts et al. 2001; McDonald et al. 2008). Ants are an ideal organism for monitoring changes in biodiversity related to land-use change due to their ubiquitous nature, high diversity, and their role as bioindicators. The goal of this study was to assess the diversity of the …


The Bgs 13 Mutant Of Pichia Pastoris And Its Effect On Structural Changes Of The Reporter Protein B-Lactogolbulin, Bushra Irshad Jan 2022

The Bgs 13 Mutant Of Pichia Pastoris And Its Effect On Structural Changes Of The Reporter Protein B-Lactogolbulin, Bushra Irshad

University of the Pacific Theses and Dissertations

Pichia pastoris, a methylotrophic yeast, is an ideal host for recombinant protein expression. It has the capability of performing many eukaryotic post-translational modifications and grows to high cell densities. However, P. pastoris’s secretion properties are not always efficient, and its secretory pathway mechanisms have not been thoroughly elucidated. A previously identified mutant strain, bgs13, was found to efficiently secrete most recombinant proteins tested, raising the possibility that this bgs13 mutant is a universal super secreter and understanding its secretion process is needed. In this study, we used a reporter protein, ?-lactoglobulin (b-LG), to perform structural analysis and comparisons of protein …


How Do They Do It? Using Omics Approaches To Explore Metabolic Responses Associated With Hypoxia And Exercise Tolerance In The Deepest Diving Pinniped, Elizabeth R. Piotrowski Jan 2022

How Do They Do It? Using Omics Approaches To Explore Metabolic Responses Associated With Hypoxia And Exercise Tolerance In The Deepest Diving Pinniped, Elizabeth R. Piotrowski

University of the Pacific Theses and Dissertations

Marine mammals such as northern elephant seals (NES) routinely experience hypoxemia and ischemia-reperfusion events to many tissues during deep dives with no apparent adverse effects. Adaptations to diving include increased antioxidants and elevated oxygen storage capacity associated with high hemoprotein content in blood and muscle. Despite experiencing decreased oxygen tensions during diving, NES likely rely on the mobilization of large lipids stores and catabolism of fatty acids to provide energy to exercising muscle while diving. To identify potential regulatory mechanisms that may underly hypoxia and exercise tolerance in diving mammals, this study used system-wide approaches to characterize changes in genes …


The Role Of Rad51 In Trichomonas Vaginalis, Dominique Hall Jan 2022

The Role Of Rad51 In Trichomonas Vaginalis, Dominique Hall

University of the Pacific Theses and Dissertations

Drug resistance to the current treatments on the market is on the rise, therefore there is strong interest in understanding what could be causing the resistance, how resistance could be spreading through the population, and finding some possible new drug targets. One protein of interest is Radiation Sensitive Protein 51 (Rad51). It is a protein that is involved in homologous recombination as well as other processes such as DNA damage repair. While Trichomonas vaginalis traditionally has been known to replicate via binary fission, a modified form of closed mitosis, there is some evidence that meiosis, or at least some form …