Life Sciences Commons^™

Investigating The Impact Of Oxidative Stress On Tetrahymena Thermophila Sirtuin,Thd 18, Emmanuel Dubuisson

Publications and Research

Sirtuins are a family of enzymes that fulfill various important biological functions. Investigators have looked for the implication of Sirtuin genes in cell signaling mechanisms, in the formation and silencing of heterochromatin, in the regulation of ion channels, and in the modulation of the cellular redox reactions[2]. Different model organisms have been previously used to conduct these studies; among them, there are yeasts, nematodes, and fruit flies. Each one has made some valuable contribution into the vast body of knowledge related to this field.

However, gaps in the understanding of Sirtuins functions still remain to be filled. In this optic, …

How Soil Salinity Affects The Stomatal Conductance Of Baccharis Salicifolia (Mulefat/Seepwillow), Andrew Kim, Caroline Wilkerson, Mahala Bayless, Peter Du

Featured Research

This is a poster presentation demonstrating the project our group has been working on. We hypothesize that the stomatal conductance of mulefat will decrease as soil salinity increases in both pre-rain and post-rain conditions because the plant tries to absorb salt water. However, the salt water cannot pass through plant tissue and draws water out of the plant. Since plant requires water for photosynthesis, water being drawn out means less water is available for the plant to do photosynthesis. We have tested our hypothesis by collecting soil samples in Legacy park, and recorded stomatal conductance by using a leaf porometer

How Soil Salinity Affects The Stomatal Conductance Of Baccharis Salicifolia (Mulefat/Seepwillow), Andrew Kim, Caroline Wilkerson, Mahala Bayless, Peter Du

Featured Research

This is a poster presentation demonstrating the project our group has been working on. We hypothesize that the stomatal conductance of mulefat will decrease as soil salinity increases in both pre-rain and post-rain conditions because the plant tries to absorb salt water. However, the salt water cannot pass through plant tissue and draws water out of the plant. Since plant requires water for photosynthesis, water being drawn out means less water is available for the plant to do photosynthesis. We have tested our hypothesis by collecting soil samples in Legacy park, and recorded stomatal conductance by using a leaf porometer

A Comparison Of Different Methods Of Dehydration On Baccharis Salicifolia, Michael Nicholas, Sinjun Hong

Featured Research

Baccharis salicifolia is a native riparian plant living in many places near to the Santa Monica Mountains. One of these locations is Legacy park, which has had many events effect it that has led to some very unfortunate changes. The park’s soil was tested earlier this year by a group of undergraduate students lead by Dr. Stephen Davis and was found to have a very high salinity level. The plants in the park appeared to be struggling to survive and had signs of dehydration and wilting. This led to us questioning the types of dehydration of the plants. Areas of …

A Comparison Of Photosynthetic Rate, Stomatal Conductance, And 
Electron Transport Rate Between Malosma Laurina And Encelia Californica, Yujin Choi, Isabella Armstrong, Catherina Haas, Micah Kim

Featured Research

In the Santa Monica Mountains, there are two main vegetation types: chaparral, which makes up __% of plants in these mountains, and coastal sagebrush, which makes up __%. Despite California’s acute environmental stress, both of these plants manage to survive, and even thrive in some cases. We were interested in seeing if in spite of these vast anatomical and physiological differences, these plants were able to survive at similar health rates, measured in photosynthetic rate, stomatal conductance, and electron transport rate (ETR). We have decided to choose 2 plants from 2 different leaf types of different vegetation types: Malosma laurina …

Comparison Of Photosynthesis, Stomatal Conductance, And Water Potential Between Native Rhus Integrifolia And Invasive Nicotiana Glauca, Tiffany J. Egbo, Emma J. Navarro, Malaun A. Phillips, Cameron I. Zohary

Featured Research

Invasive species, such as Nicotiana glauca, are a prominent part of the Santa Monica Mountains, and could be responsible for displacing native species such as Rhus integrifolia. It was observed in the field that Nicotiana glauca was doing better than Rhus integrifolia, so our group decided to indirectly test this. Because of the invasiveness of its species, it is essential to measure the health of a native species to see if the invasive species is posing as a massive threat. Water potential, stomatal conductance, fluorescence, photosynthetic rates and electron transport rates were compared among the two plants …

Effects Of Evolution On Laboratory Sublines Of Myxococcus Xanthus Dk1622, Mackenzie Ryan, Francesca Scribano, Kimberly Murphy

Celebration of Learning

Microbes have served as effective models for studying evolution because of their ability to be easily replicated, stored, and manipulated. Myxococcus xanthus is a soil bacterium that has served as a model organism in many laboratories. The unique social and motile behaviors exhibited by this bacterium make it ideal for phenotypic assays. A wild-type strain of M. xanthus, DK1622, has been distributed to laboratories across the United States and therefore we now have DK1622 sublines. The genomes of a number of these sublines have been sequenced and their social and motile phenotypes have been analyzed. When nine of these sublines …

_Chemosensory Role Of A Reproductive Hormone- Associating Gnrh Neurons With Taste And Olfactory Systems In Teleost Fish Format 2.Pptx, Gabriel Mchugh

Gabriel McHugh

A Student’S Perspective On Engagement In Ecological Research During Their First Semester In College, Natalie M. Aguirre, Karagan L. Smith, Cristian M. Garcia, Cheryl Swift, Stephen D. Davis

Biology

Pepperdine University and Whittier College jointly initiated a new first-year seminar series in the fall of 2016 that engaged students in authentic research, their first semester on campus. The goals are listed below. Assessment of these goals included both qualitative focus groups and quantitative survey questionnaires administered by an outside assessment agency, WestEd.org.

Ninety-two percent of students reported that their first-year seminar improved learning in concurrent courses and ninety to ninety-three percent of students said their first-year seminar increased their interest in STEM. In addition, students self-reported a significant improvement in all aspects of their ability to plan and conduct …

Post Drought Recovery In Malosma Laurina After Severe Dieback During California’S Historic Drought Of 2012-2016, Karagan L. Smith, Guinevere X. Mesh, Natalie M. Aguirre, Gabriella N. Palmeri, Helen I. Holmlund, Stephen D. Davis

Biology

Malosma laurina is a species of chaparral shrub that dominates coastal exposures of the Santa Monica Mountains of southern California. Between 2012 and 2016, protracted drought with half normal rainfall over a five-year period (175 mm), led to severe dieback, exceeding 50% whole plant mortality at some sites. The drought dissipated in 2017 with an annual rainfall that exceeded the 140-yr normal by 108 mm. As a result of this elevated annual rainfall in 2017, we were interested in documenting the potential for full recovery of Malosma laurina as a keystone species of coastal chaparral shrub communities. We tested the …

Urban Biogeography Of Fungal Endophytes In Metrosideros Excelsa Across San Francisco, Emma Gibson

Creative Activity and Research Day - CARD

Trees in cities confer health and psychological benefits to the city's inhabitants, so the urban forest is a major component of human health in urban settings. Previous studies have shown that environmental factors can impact endophytic (within-plant) microbial communities of forest trees, but the effects that urban environmental factors may have on these communities are not well understood. Here, we characterized asymptomatic fungal communities in 30 individual Metrosideros excelsa trees from 6 distinct sites using culturing and molecular methods. We found high community diversity both within and among sites, and several patterns within these communities. For example, we found similarities …

Bioaccumulation Of Zinc In Bermuda Grass (Cynodon Dactylon), Drew Fisher, H. Marie Surratt, Louise Gebauer, Andrew Palaski

Featured Research

Phytoremediation is the plant based process to remove toxins such as heavy metals from the soil. In this experiment, we hypothesized Bermuda grass (Cyndon dactylon) will absorb a detectable level of zinc, a nontoxic metal, from the soil. We grew two separate groups of grass: the control and the experimental, which was watered with zinc acetate. Neither of the groups produced enough yield within the weeks given to the experiment, but if it went according to plan, we would have used flame atomic absorption spectroscopy to evaluate the relative concentrations of zinc. Significant uptake of zinc could reveal a possible …

A Comparison Of Electron Transport Rate, Photosynthetically Active Radiation, Light-Adapted Fluorescence, And Dark-Adapted Fluorescence Between Stipa Pulchra And Pennisetium Setaceum, Sydney Adams, Brandon Chuck, Agatha Heng, Amelia Vento, Stephen D. Davis

Featured Research

The purpose of this investigation was to provide an explanation into how the invasive species Pennisetium setaceum, Fountain Grass, is able to outcompete the native California grassland species Stipa pulchra, Purple Needle Grass. We used a light adapted and a dark adapted fluorometer to measure the photosynthetic radiation (PAR), leaf temperature, alpha (α), light adapted fluorescence (Fv’/Fm’), dark adapted fluorescence (Fv/Fm), and the electron transport rate (ETR) on young Fountain Grass and Purple Needlegrass. After collecting and analyzing the data, we concluded that the dark adapted fluorescence (Fv/Fm) was the only statistically significant measurement where the Fv/Fm of …

The Effects Of Soil Suffused With Cool-Fire Ash On The Germination And Early Growth Of Radish Seedlings, Ryan Dalforno, Braden Ritchey, Jay Ogle

Featured Research

In this study, the effects of cool fire ash in soil with varying amounts of water were observed in terms of the germination and early growth of garden radish (Raphanus raphanistrum subsp. sativus) seedlings. Measurements regarding plant growth, field capacity, and seedling leaf quantum yield were taken and compared between four (4) trios of pots separately containing radish seedlings planted in ashy and frequently-watered soil (A_w), ashy and infrequently-watered soil (A_d), normal unmodified garden soil that was watered frequently (N_w) and normal soil that was watered infrequently (N_d). While the …

Creating A Predictive Model For Flowering Of Virginia Orchid, Cypripedium Pubescens, Emily Horton

Student Scholar Showcase

No abstract provided.

Evaluating Effects Of Gene Mutation And Light Intensity On Arabidopsis Thaliana Development, Carolanne Bekus

Student Scholar Showcase

The completion of sequencing Arabidopsis thaliana’s genome has led to the next crucial challenge of determining gene function in these plants. A. thaliana is a model organism often compared to commercial crops. The discovery of gene function within these plants will aid in giving insight on how gene function can affect commercial crop production. Presented here is an analysis comparing wild-type Columbia (Col-O), to single gene mutants when knocking-out transcriptional factors VPI/ABI3-like 1 (val1) and basic region/leucine zipper motif (bZIP). These single gene mutations may affect several traits that in turn can result in morphological changes and/or …

Analysis Of Downstream Signaling Of Tlrs After U0126 Inhibition, Brandy Frazier

Student Scholar Showcase

Francisella tularensis (F. tularensis) is a pathogenic bacterium which causes the disease tularemia. F. tularensis is thought to be able to enter and multiply inside of liver cells because it interacts with toll-like receptors (TLRs). Examining the signaling pathway downstream of the TLRs will allow for better understanding of how this disease works and possible treatment strategies. In this study I propose to examine how molecular inhibitors affect signaling downstream of TLRs in HepG2 cells treated with lipopolysaccharides (LPS) from E. coli. Mitogen-activated protein kinase is a cellular molecule in signaling cascades that directs cellular response mechanisms. MAPK can be …

Association Of Vasp Polymorphisms And Infectious Disease Burden In Global Populations And Identification Of Candidate Resistance Haplotypes In Sub-Saharan Africa, Melinda Phun, Blake Rosenn, Danny Glenn, Dhanushi Rupasinghe, James Church, David Zuzga, Shaohua Fan, Sarah Tishkoff

HON499 projects

Enteric pathogens employ numerous strategies to breach the intestinal epithelial barrier. One critical target of these pathogens is the host cell cytoskeleton. Pathogens may induce cytoskeletal remodeling to disrupt tight junctions and increase the permeability of the epithelium to gain access to underlying tissue. Alternatively, the cytoskeletal machinery may be directly co-opted to facilitate the attachment, invasion, or intracellular motility of these pathogens. The vasodilator-stimulated phosphoprotein (VASP) is a processive actin polymerase that induces membrane remodeling through the polymerization of actin cytoskeletal filaments. Interestingly, VASP is regulated by a variety of pathogens to induce cytoskeletal remodeling in host cells. If …

Investigation Of Antimicrobial Properties Of Rhus Ovata Extracts, Sydney T. Adams

Seaver College Research And Scholarly Achievement Symposium

Native peoples of Southern California historically used a variety of local plants as remedies for illnesses. Chaparral species such as Rhus ovata (sugar bush) were widely available and were used to ease headaches, coughs and chest pains, and colds. In light of the historical importance of this plant and other chaparral species, recent fungal pathogen-induced diebacks of Malosma laurina, a species closely related to R. ovata, have raised questions regarding the innate defenses of these plants against fungal pathogens. We attempted to scientifically evaluate the traditional medicinal use of R. ovata and its antifungal resistance by testing two …

Potential Spread Of The Fungal Pathogen Botryospharea Dothidea From Chaparral Shrubs To Grape Vineyards In The Santa Monica Mountains, Alexandra N. Case, Natalie M. Aguirre, Rodney L. Honeycutt, Stephen D. Davis

Seaver College Research And Scholarly Achievement Symposium

We tested the hypothesis that an opportunistic endophytic fungus, Botryosphaeria dothidea, that frequently infects and causes dieback in species of chaparral shrubs in the Santa Monica Mountains during drought events, may spread to grape vineyards in the Santa Monica Mountains. Recently a dominant chaparral species in coastal exposures of the Santa Monica Mountains, Malosma laurina, has undergone extensive dieback in low elevation, dry sites, in response to historic drought in California, but less dieback in high elevation moist sites. M. laurina frequently grows adjacent grape vineyards. Thus we hypothesized that fungal isolates from a low elevation, dry vineyard …

Testing For The Presence Of Botryosphaeria Dothidea In Branches Of Ceanothus Spinosus Undergoing Dieback, Brandon R. Grinovich, Chelsea N. Puncochar, Katarina L. Carter, Stephen D. Davis, Rodney L. Honeycutt, Talia A. Cao, Karagan L. Smith

Featured Research

Botryosphaeria dothidea is an opportunistic pathogen found in some of the cavitated branches of the vegetation in the Santa Monica Mountains. In this study, we focused on finding the presence of Botryosphaeria dothidea in Ceanothus spinosus located on Pepperdine University’s campus. We wanted to test this hypothesis because we observed a large amount of dieback in the Ceanothus spinosus population and wanted to identify a possible contributor. Because of the large number of cavitated branches the Ceanothus spinosus contained, we hypothesized they contained fungus. To test this, we took twenty samples of twenty different Ceanothus spinosus, isolated the fungus …

Dynamic Modeling And Stochastic Simulation Of Metabolic Networks, Emalie Clement

UNO Student Research and Creative Activity Fair

Throughout our current generation, scientific studies, with the help of increased technological methods, have enabled the investigation of biology at nanoscale levels. Nevertheless, such systems necessitate the use of computational methods to comprehend the complex interactions occurring. Traditionally, dynamics of metabolic systems are described by ordinary differential equations producing a deterministic result which negates the intrinsic heterogeneity of intracellular systems. More recently, stochastic modeling approaches have gained popularity with the capability of providing more realistic outcomes. Yet, solving stochastic algorithms tend to be computationally intensive processes. Employing the queueing theory, an approach commonly used to evaluate telecommunication networks, reduces the …

Studies Of Amino Acid Mutations In Drug Resistance Of The Smo Protein, Eunice Wintona

UNO Student Research and Creative Activity Fair

Smoothened receptor (SMO) is a protein that in humans, is encoded by the SMO gene. A systemic mutation in its binding pocket helps predict the sensitivity of mutant proteins to different drugs. Known as a GPCR-like receptor, it is a component of the hedgehog signaling pathway; a pathway involved in body patterning and the regulation of adult stem cells. An uncontrolled or inappropriate activation of the Hedgehog pathway drives tumor progression in cancers and a number of birth defects. To achieve these goals, the molecular modeling software MOE was used to build small molecules and drug molecules like Vismodegib and …