Life Sciences Commons^™

Developmental Increase In 3h-Muscimol Binding To The Γ-Aminobutyric Acida Receptor In Hypothalamic And Limbic Areas Of The Rat: Why Is The Ventromedial Nucleus Of The Hypothalamus An Exception?, Aline Davis, Margaret Mccarthy

Aline Davis

Using in vitro autoradiography to measure binding of the γ-aminobutyric acidA (GABAA) receptor agonist, muscimol, we examined male and female rats on postnatal days 1, 5, 10, and 20. There were no sex differences in muscimol binding in any hypothalamic or limbic regions examined. However, all regions exhibited a developmental increase in the density of binding, except the ventromedial nucleus (VMN) of the hypothalamus. We have previously shown that the adult VMN is the only hypothalamic nucleus containing an abundance of the α2 subunit of the GABAA receptor and lack of the α1 subunit. We hypothesize that the lack of …

Loss Of Steroidogenic Factor 1 Alters Cellular Topography In The Mouse Ventromedial Nucleus Of The Hypothalamus, Aline Davis, Marianne Seney, Nancy Stallings, Liping Zhao, Keith Parker, Stuart Tobet

Aline Davis

Knockout (KO) mice lacking the orphan nuclear receptor steroidogenic factor 1 (SF-1) exhibit marked structural abnormalities of the ventromedial nucleus of the hypothalamus (VMH). In this study, we sought to determine the molecular mechanisms underlying the VMH abnormalities. To trace SF-1-expressing neurons, we used a SF-1/enhanced green fluorescent protein (eGFP) transgene. Although the total numbers of eGFP-positive cells in wild-type (WT) and SF-1 KO mice were indistinguishable, cells that normally localize precisely within the VMH were scattered more diffusely in adjacent regions in SF-1 KO mice. This abnormal distribution is likely due to the loss of SF-1 expression in VMH …

Integrating Art And Science In Undergraduate Education, Daniel Gurnon

Chemistry & Biochemistry Faculty Publications

The prevailing vision for undergraduate science education includes increased collaboration among teachers of science, technology, engineering and math (STEM) and an overhaul of introductory courses [1]–[4]. But by staying within the borders of STEM, are we overlooking connections between the arts and innovative science? Likewise, are we missing an important opportunity to inspire and inform nonscientists? Here we explore how weaving the visual arts into a science curriculum can both help develop scientific imagination and engage nonscientists. As an example, we describe a recent collaboration between artists and scientists to create a series of science-inspired sculptures.

S-Adenosyl-L-Methionine Protects The Probiotic Yest, Saccharomyces Boulardii, From Acid-Induced Cell Death, Nicanor Austriaco, Vincent Cascio, Daniel Gittings, Kristen Merloni, David Laprade

Biology Faculty Publications

Background

Saccharomyces boulardii is a probiotic yeast routinely used to prevent and to treat gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. However, only 1-3% of the yeast administered orally is recovered alive in the feces suggesting that this yeast is unable to survive the acidic environment of the gastrointestinal tract.

Results

We provide evidence that suggests that S. boulardii undergoes programmed cell death (PCD) in acidic environments, which is accompanied by the generation of reactive oxygen species and the appearance of caspase-like activity. To better understand the mechanism of cell death at the molecular level, we …

Dictyostelium Development Shows A Novel Pattern Of Evolutionary Conservation, Xiangjun Tian, Joan E. Strassmann, David C. Queller

Biology Faculty Publications & Presentations

von Baer's law states that early stages of animal development are the most conserved. More recent evidence supports a modified "hourglass" pattern in which an early but somewhat later stage is most conserved. Both patterns have been explained by the relative complexity of either temporal or spatial interactions; the greatest conservation and lowest evolvability occur at the time of the most complex interactions, because these cause larger effects that are harder for selection to alter. This general kind of explanation might apply universally across independent multicellular systems, as supported by the recent finding of the hourglass pattern in plants. We …

You’Ll Find No Answers Here, Joseph M. Morelli

Masters Theses 1911 - February 2014

One Studio Art graduate student's slog through the disciplines of art and science; noting the similarities, overlaps, and differences, and becoming utterly flummoxed in the process. It's about coming to terms with not knowing a whole lot about anything, really, but pressing on regardless.

Comparison Of Th1 Cytokines And T Cell Markers Gene Expressions Between Virulent And An Attenuated Eiav Vaccine Strain, Talia R. Henkle

Lewis Honors College Capstone Collection

The equine infectious anemia virus (EIAV) is closely related to HIV and has been used as a model to identify protective mechanisms against lentivirus infection. In horses, EIA infection progresses for about a year before infected horses manage to control virus replication. This naturally-gained protection is absolutely dependent on active immune responses as evidenced by the fact that immunosuppressive drugs can induce the recurrence of disease. As the resolution of initial viremia correlates with the appearance of virus specific cytotoxic T lymphocytes (CTL), we believe that cellular immune responses play a key role in controlling EIAV in the horse. In …

Full Issue: Volume 6, Number 2

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.

Full Issue: Volume 7, Number 1

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.

Emerging Technologies For Non-Invasive Quantification Of Physiological Oxygen Transport In Plants, P. Chaturvedi, M. Taguchi, S. L. Burrs, B. A. Hauser, W.W. A.W. Salim, Jonathan C. Claussen, E. S. Mclamore

Jonathan C. Claussen

Oxygen plays a critical role in plant metabolism, stress response/signaling, and adaptation to environmental changes (Lambers and Colmer, Plant Soil 274:7-15, 2005; Pitzschke et al., Antioxid Redox Signal 8:1757-1764, 2006; Van Breusegem et al., Plant Sci 161:405-414, 2001). Reactive oxygen species (ROS), by-products of various metabolic pathways in which oxygen is a key molecule, are produced during adaptation responses to environmental stress. While much is known about plant adaptation to stress (e.g., detoxifying enzymes, antioxidant production), the link between ROS metabolism, O2 transport, and stress response mechanisms is unknown. Thus, non-invasive technologies for measuring O2 are critical for understanding the …

Regulation Of Antigenic Variation In Trypanosoma Brucei, Imaan A. Benmerzouga

ETD Archive

Trypanosoma brucei is a protozoan parasite that causes sleeping sickness in humans and nagana in cattle. When inside the mammalian host, T. brucei cells stay in extracellular spaces and regularly switch their surface antigen, Variant Surface Glycoprotein (VSG), to escape the host's immune responses. To ensure the effectiveness of VSG switching, T. brucei expresses a single type of VSG at any time exclusively from one of 20 identical VSG expression sites located next to the telomere. Monoallelic expression of VSG and VSG switching are important for T. brucei's pathogenesis. Our major goal is to understand the mechanisms of antigenic variation …

Bioinformatic Analysis And In Vitro Expression Of Malaria Parasite Translocon And Ribonuclease Binding-Like Rhoptry Genes, Moses Z. Timta

ETD Archive

Malaria caused by the parasite Plasmodium, still remains a significant public health problem worldwide, due to lack of a vaccine and emerging drug and insecticide resistance, among malaria parasites and mosquito vectors, respectively. Rhoptry proteins of Plasmodium enable merozoite invasion of host erythrocytes. However, only a few of these proteins have been characterized. Thirty-six P. yoelii merozoite rhoptry proteins were identified as putative rhoptry proteins by proteome analysis. Some of these proteins have been characterized while others still remain an intense area of active research. Molecular characterization and understanding of these novel proteins may assist in vaccine development, design of …

A Comparison Of Water Availability In Coastal Live Oak (Quercus Agrifolia) And California Bay (Umbellularia Californica) At Top And Bottom Of Hillsides At Malibu Creek State Park, California, Jake Szarzynski, Marley Biyendolo, Jeremy Goldenetz, Ann Alcazar

Featured Research

This investigation serves to show whether moisture content is different in plants at the top of hills versus bottom of hills, specifically comparing values of Quercus agrifolia and Umbellularia californica in Malibu Creek State Park. By acquiring six branches of each species on a hill at intervals of twenty feet, the moisture content can be obtained and analyzed by using the Scholander Hammel pressure chamber. This allows us to determine whether there is a correlation between moisture content and plant position on hills.

Varying Carbon Dioxide Levels And Its Effects On Malsoma Laurina’S Photosynthetic Rate, John A. Lawlor, Dustyn T. Zierman-Felix, Michael P. Schlagel

Featured Research

The Keeling Curve has displayed an exponential increase in carbon dioxide within the earth’s atmosphere since the late 1950’s. Scientists have heatedly debated the effects that will occur as a result of this relatively new phenomenon (since the Industrial Revolution of America). We tested the effect of increased carbon dioxide levels on plant life, Malosma laurina, in particular. Our experiment involved the application of 400 PPM of carbon dioxide into different specimens of M. laurina and 800 PPM of carbon dioxide into the same specimens. We then recorded the rate of photosynthesis, conductance results, and levels of internal carbon dioxide. …

Difference In Water Status Between Oak Trees (Quercus Berberidifolia) With Brown And Green Leaves During Severe Drought, Mia Bryant, Hannah Dario, Cameron Kline

Featured Research

In this experiment, we examined cavitation in Quercus berberidifolia plants. We hypothesized that as the amount of water stress increases, then the pressure to cause embolism will decrease. We thought this because as a plant loses more water, the more air bubbles will form within the plant and therefore the pressure to cause this will decrease. We tested this hypothesis by comparing dry Quercus berberidifolia to more hydrated Quercus berberidifolia in Tapia Park, near Malibu, California. We measured and compared these plants by the use of the Scholander Pressure chamber and a parometer. In the end, we discovered that our …

Impact Of Reclaimed Water On Photosynthetic Performance In Green Bark Ceanothus (Ceanothus Spinosus), Erika De Leener, Michael L. Gribble, Joshua D. Volkmar, Luo J. Zhao

Featured Research

The sprinkled water on the campus of Pepperdine University is primarily reclaimed water from sinks, toilets and showers on campus. The water is treated with micro bacteria and sand rocks to remove larger particles, smaller nitrogen containing compounds, excess nutrients and human pathogens. The Mediterranean weather in Southern California is characterized by dry summers, and watering plants by reclaimed water helps relieve the water stress in the community. However, the reclaimed water might distort the normal physiology of native plants on campus. We hypothesize that because nitrogen containing compounds cannot be efficiently removed by micro bacteria, higher nitrogen content in …

A Mesh Generation And Machine Learning Framework For Drosophila Gene Expression Pattern Image Analysis, Wenlu Zhang, Daming Feng, Rongjian Li, Andrey Chernikov, Nikos Chrisochoides, Christopher Osgood, Charlotte Konikoff, Stuart Newfeld, Sudhir Kumar, Shuiwang Ji

Computer Science Faculty Publications

Background: Multicellular organisms consist of cells of many different types that are established during development. Each type of cell is characterized by the unique combination of expressed gene products as a result of spatiotemporal gene regulation. Currently, a fundamental challenge in regulatory biology is to elucidate the gene expression controls that generate the complex body plans during development. Recent advances in high-throughput biotechnologies have generated spatiotemporal expression patterns for thousands of genes in the model organism fruit fly Drosophila melanogaster. Existing qualitative methods enhanced by a quantitative analysis based on computational tools we present in this paper would provide …

Biology And Ecology Of Glyphosate-Resistant Giant Ragweed, Kabelo Segobye

Open Access Theses

Giant ragweed (Ambrosia trifida L.) is a competitive annual plant found in disturbed landscapes and is the most troublesome weed in Indiana and the US Corn Belt. It is one of the most common and problematic weeds in corn and soybean production. The introduction of herbicide glyphosate, N-(phosphonomethyl) glycine in early 1970's provided farmers with a better and low-cost tool to control weeds. The use of glyphosate drastically increased after the development of glyphosate resistant agronomic crops in 1996 and was use as a post-emergence selective herbicide. This led to overreliance and repeated use of glyphosate for weed control especially …

Lifelines Winter 2013, Southern Adventist University

Lifelines - Biology Department Newsletter

The Winter 2013 issue of Lifelines features updates on research being conducted in the Biology Department, updates to the Biology Trail, student missions to Familia Feliz in Bolivia, and a pictorial directory of the 2013 biology and allied health graduates.

Post-Fire Recovery Of Juglans Californica In Sycamore Canyon: Water Potential And Site Characterization, Ariel Lan, Caitlin Thompson, Victoria Lekson

Featured Research

Our study focused on post-fire recovery in the California Black Walnut, Juglans californica. Our study was conducted Sycamore Canyon, an area of the Santa Monica Mountain Range recently damaged by the April 2013 fires. Part of our study focused on water potential and water stress among J. californica; we examined differences in the water potentials of mature, unburned trees and resprouts which have grown since the fires in April. We found that mature trees have a significantly higher water potential than sprouts, either epicormic or basal, which indicates that they are better equipped to handle water stress. We also found …

Post-Fire Recovery Of Juglans Californica In Sycamore Canyon: Vessel Length, Shading, Water Use Efficiency And Water Status, Victoria Lekson, Anushree Mahajan

Featured Research

In April 2013, Sycamore Canyon experienced a major wildfire. This study investigates post-fire recovery of two types of resprouts, basal and epicormic, and compares multiple parameters to mature unburned Juglans californica. In this study, we investigate the influence of time of day on the post-fire water potential of mature unburned plants versus burned Juglans californica epicormic and basal resprouts. One way ANOVA test reveals p

The Effect Of Freezing Conditions On Xylem Diameter Of Malosma Laurina And Umbellularia Californica In The Santa Monica Mountains, Nicole A.P.M.K.O.M. Nakamatsu, Theadora V. Ordog, Kaitlyn E. Sauer

Featured Research

Temperature variations in the Santa Monica Mountains are drastic at times, which may be affecting the local plants. To determine the repercussions of these variations in temperature, we measured the xylem diameters of freezing and non-freezing Malosma laurina and Umbellularia californica. U. californica was chosen because it has a large xylem diameter, yet is known to survive freezing conditions. We thought that this plant could provide the most significant results to prove or disprove our hypothesis. M. laurina was chosen because it is abundant in the Santa Monica Mountains and has different physical dimensions than U. californica. Smaller xylem diameters …

A New Social Gene In Dictyostelium Discoideum, Chtb, Lorenzo A. Santorelli, Adam Kuspa, Gad Shaulsky, David C. Queller, Joan E. Strassmann

Biology Faculty Publications & Presentations

BACKGROUND:

Competitive social interactions are ubiquitous in nature, but their genetic basis is difficult to determine. Much can be learned from single gene knockouts in a eukaryote microbe. The mutants can be competed with the parent to discern the social impact of that specific gene. Dictyostelium discoideum is a social amoeba that exhibits cooperative behavior in the construction of a multicellular fruiting body. It is a good model organism to study the genetic basis of cooperation since it has a sequenced genome and it is amenable to genetic manipulation. When two strains of D. discoideum are mixed, a cheater strain …

“Culling The Herd”: Eugenics And The Conservation Movement In The United States, 1900–1940, Garland E. Allen

Biology Faculty Publications & Presentations

While from a late twentieth- and early twenty-first century perspective, the ideologies of eugenics (controlled reproduction to eliminate the genetically unfit and promote the reproduction of the genetically fit) and environmental conservation and preservation, may seem incompatible, they were promoted simultaneously by a number of figures in the progressive era in the decades between 1900 and 1950. Common to the two movements were the desire to preserve the ‘‘best’’ in both the germ plasm of the human population and natural environments (including not only natural resources, but also undisturbed nature preserves such as state and national parks and forests). In …

Aaron Gillette , Eugenics And The Nature Nurture Debate In The Twentieth Century, Garland E. Allen

Biology Faculty Publications & Presentations

Aaron Gillette, Eugenics and the Nature–Nurture Debate in the Twentieth Century, Palgrave Studies in the History of Science and Technology [2007], digital reprint (New York, NY: Palgrave Macmillan, 2010), pp. ix, 239, index, £18.99, paperback, ISBN: 9780230108455. This book treats an important subject – the history of the nature–nurture debate (focused on the US but with references to European players and movements) – and its implications for current theories of evolutionary psychology.

A Bacterial Symbiont Is Converted From An Inedible Producer Of Beneficial Molecules Into Food By A Single Mutation In The Gaca Gene, Pierre Stallforth, Debra A. Brock, Alexandra M. Cantley, Xiangjun Tian, David C. Queller, Joan E. Strassmann, Jon Clardy

Biology Faculty Publications & Presentations

Stable multipartite mutualistic associations require that all partners benefit. We show that a single mutational step is sufficient to turn a symbiotic bacterium from an inedible but host-beneficial secondary metabolite producer into a host food source. The bacteria's host is a "farmer" clone of the social amoeba Dictyostelium discoideum that carries and disperses bacteria during its spore stage. Associated with the farmer are two strains of Pseudomonas fluorescens, only one of which serves as a food source. The other strain produces diffusible small molecules: pyrrolnitrin, a known antifungal agent, and a chromene that potently enhances the farmer's spore production and …

Greater Sexual Reproduction Contributes To Differences In Demography Of Invasive Plants And Their Noninvasive Relatives, Jean H. Burns, Eleanor A. Pardini, Michele R. Schutzenhofer, Y Anny Chung, Katie J. Seidler, Tiffany M. Knight

Biology Faculty Publications & Presentations

An understanding of the demographic processes contributing to invasions would improve our mechanistic understanding of the invasion process and improve the efficiency of prevention and control efforts. However, field comparisons of the demography of invasive and noninvasive species have not previously been conducted. We compared the in situ demography of 17 introduced plant species in St. Louis, Missouri, USA, to contrast the demographic patterns of invasive species with their less invasive relatives across a broad sample of angiosperms. Using herbarium records to estimate spread rates, we found higher maximum spread rates in the landscape for species classified a priori as …

Family Matters: An Analysis Of Genetic Relatedness Of Tetraclita Rubescens (The Pink Volcano Barnacle) Over Several Spatial Scales At Monterey And Bodega Bay, California, Kelly N. Chang

Scripps Senior Theses

Inbreeding involves the mating of closely related individuals at a higher frequency than at random; this can decrease the average fitness of populations and individuals by reducing the presence of heterozygotes and augmenting the expression of deleterious genes. Since marine invertebrates exhibit widespread dispersal, their potential for inbreeding is often disregarded. The adult sessile state of barnacles creates the potential for inbreeding as a result of necessary copulation between neighboring individuals. Depending on the degree of mixing that occurs during dispersal, closely related individuals or siblings may settle in close proximity, generating the possibility of kin aggregation and consequent inbreeding. …

A Reassessment Of The Conservation Status Of A Critically Endangered Neotropical Frog, Mannophryne Olmonae, Using Occupancy Modeling Techniques, Jessica Mcquigg

Senior Independent Study Theses

Amphibian species worldwide are threatened with decline and extinction, making species monitoring an important scientific endeavor. The Bloody Bay Poison Frog, Mannophryne olmonae, a Tobago island endemic, was identified as critically endangered by the IUCN in 2004. Recent evidence suggests that a less severe conservation status may be appropriate for M. olmonae. This study employs acoustic calling surveys, land-use information, and multi-year (2011 and 2012) occupancy modeling techniques to propose an appropriate conservation status for this species. This study suggests that M. olmonae occupies a larger geographic range than was previously thought, and is not experiencing population declines. …

Flying Speed In Drosophila Melanogaster Selected For Fast Flight, Jess Wheeler Ms

All Student Scholarship

The aim of this study was to quantify the increase in flying speed in two replicate lines of Drosophila melanogaster (AA1 and AA2), after approximately 520 generations of selection for fast flight in a wind tunnel.