Life Sciences Commons^™

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 …

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 …

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 …

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 …

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

Biology Faculty Research

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.

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. …

Phylogeography Of The Malagasy Ant Species Otontomachus Coquereli, Jason Jackson

Electronic Theses and Dissertations

Madagascar is an extremely diverse and geographically complex area boasting levels of endemism that blatantly raise questions about their origins. There is evidence that these endemics arose via insitu diversification during Madagascar's ~88 million year isolation, even though it was essentially in the middle of Gondwana with ample opportunity to acquire inhabitants. Madagascar's high levels of diversity and endemism make it an ideal location to study speciation, especially considering the evidence that such high levels speciation occurred in Madagascar itself. Several hypotheses have been formulated to relate the complex geography to genetic divergence, and thereby speciation. I explore three hypotheses …

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

Biology Faculty Research

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 Research

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 …

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 Research

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 …

Sturgis And Kay Mckeever Papers, Zach S. Henderson Library Special Collections

Finding Aids

This collection consists of the papers of Georgia Southern University biology professor Sturgis McKeever and other materials related to the McKeever family, particularly his wife, Kay McKeever, and his brothers Ivan and Kermit McKeever. The materials span 1935–2005 and are predominantly professional in nature, including numerous research reprints and publications on animal species across North America, correspondence between McKeever and other researchers, and handwritten graphs, charts, and research notes. The collection also contains photographic materials, including photographic slides and negatives documenting his research. The recent accrual expands the collection to include personal correspondence between Sturgis and Kay McKeever, as well …

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 Research

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 …

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.

Likely Successors Of Ash Species In Response To The Emerald Ash Borer In Ohio Forests, Brian Michael Good

Browse all Theses and Dissertations

Invasive species have the capability to alter landscapes and change the composition of a forest in a very short time. The recent invasive pest, Agrilus planipennis, emerald ash borer, was unintentionally introduced to the United States via ship route to Michigan. The pest attacks and kills all five native ash species in Ohio. This study focused on an area in west central Ohio not yet affected by the borer. Ash centered plots were used to record all species and sizes (diameter at breast height) within a 5m radius of a central ash tree. Plots ranged in topography and all five …

Evaluating The Impact Of Fishery-Related Claw Removal On Diet, Consumption Rate, Energetics And Reproduction In The Florida Stone Crab (Menippe Spp.), Jessica Mary Hogan

Theses and Dissertations

Many global fisheries are overexploited and working towards the development of sustainable fishing methods. Claw based crab fisheries, such as the Florida stone crab (Menippe mercenaria, M. adina, and hybrids) fishery, use unique fishing techniques that reduce the overall mortality of harvested organisms. For example, the Florida stone crab fishery is regulated by requiring that fisherman only harvest crab claws and requires that fishermen return the live crab to the water following harvesting. This process takes advantage of the ability of crabs to autotomize and regenerate their claws, and enables crabs to re-enter the fishery in subsequent years if they …

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.

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. …

Taxonomy And Systematics Of New Zealand Faronitae (Coleoptera: Staphylinidae: Pselaphinae), Jong-Seok Park

LSU Doctoral Dissertations

The New Zealand Faronitae was revised at the species level, and a phylogenetic study was performed based on morphological and molecular data. Eight new genera and 143 new species were discovered. Three new genera, “Brounea”, “Ahnea” and “Pseudoexeirarthra” were designated based on the species originally described in the genus Sagola. Five new genera, “Aucklandea”, “Chandlerea”, “Nunnea”, “Leschenea” and “Pseudostenosagola” were designated by new species. Three known genera, Exeirarthra, Stenosagola and Sagola were also revised at species level. Eighty four names were synonymized, two in Exeirarthra, four in Stenosagola and 78 in Sagola. Lectotypes of seven species, Sagola terricola Broun, S. …

Comparing Biology Grades Based On Instructional Delivery And Instructor At A Community College: Face-To-Face Course Versus Online Course., Amanda Rosenzweig

LSU New Orleans Theses and Dissertations

Through distance learning, the community college system has been able to serve more students by providing educational opportunities to students who would otherwise be unable to attend college. The community college of focus in the study increased its online enrollments and online course offerings due to the growth of overall enrollment. The need and purpose of the study is to address if there is a difference in students’ grades between face-to-face and online biology related courses and if there are differences in grades between face-to-face and online biology courses taught by different instructors and the same instructor. The study also …

Secondary Structure, A Missing Component Of Sequence- Based Minimotif Definitions, David P. Sargeant, Michael R. Gryk, Mark W. Maciejewsk, Vishal Thapar, Vamsi Kundeti, Sanguthevar Rajasekaran, Pedro Romero, Keith Dunker, Shun-Cheng Li, Tomonori Kaneko, Martin Schiller

Life Sciences Faculty Research

Minimotifs are short contiguous segments of proteins that have a known biological function. The hundreds of thousands of minimotifs discovered thus far are an important part of the theoretical understanding of the specificity of protein-protein interactions, posttranslational modifications, and signal transduction that occur in cells. However, a longstanding problem is that the different abstractions of the sequence definitions do not accurately capture the specificity, despite decades of effort by many labs. We present evidence that structure is an essential component of minimotif specificity, yet is not used in minimotif definitions. Our analysis of several known minimotifs as case studies, analysis …

Lifelines Fall 2012, Southern Adventist University

Lifelines - Biology Department Newsletter

The Fall 2012 issue of Lifelines features articles on undergraduate research in biology, field ecology, and the addition of Dr. Aaron Corbit to the faculty.

The Relationship Between Leaf Mechanical Strength And Photosynthetic Rates, Aaron Van Loon, Brianna Manes, Taylor Stucky, Thomas Addington

Featured Research

Photosynthesis is the process by which plants convert light energy to chemical energy, helping sustain life in the biosphere. There are many factors that affect the rate of photosynthesis such as atmospheric CO2 concentration, temperature, and sunlight. In this experiment, we attempt to determine what effect, if any, the mechanical strength of a plant has on its rate of photosynthesis. To perform this experiment we used both the LI-COR 6400 and the Instron Mechanical Testing Device. With the LI-COR we measured photosynthetic rate of our plant subjects in real time during the prime photosynthetic hours, 10-12am. The Instron allowed us …

Effect Of Ambient Air Temperature On Leaf Size In Raphanus Sativus, Matthew Fleming, Michael Mccormack

Featured Research

Global warming is an increasing problem in today’s society. Thus, it is important to know how plants, specifically those that are cultivated for human consumption, react to rising average temperatures. This experiment tested how the leaf size of a common crop plant, Raphanus sativus (radish), is affected by two different temperatures. It is hypothesized that as temperature rises, the leaf size will increase, giving the leaf greater ability to cool via transpiration because of an larger surface area for stomatal conductance. This hypothesis was tested by growing two samples of plants in separate incubators. One sample was grown at a …

Integrating Technology, Field Experience And Collaboration In An Undergraduate Biology Research Course, Melissa M. Grigione, Dan Farkas

Cornerstone 3 Reports : Interdisciplinary Informatics

No abstract provided.

The Effect Of Leaf Trichome Density On Stem Mechanical Strength In Salvia Leucophylla, S. Mellifera, And S. Apiana, Brieanna English, Jeff Scanlon, Anushree Mahajan

Featured Research

Salvia species in southern California exhibit a variety of leaf trichome densiIes. S. mellifera, S. leucophylla, and S. apiana were chosen as study organisms because they exhibit varying trichome densiIes. A UniSpec was used to measure NDVI in leaves and an Instron was used to measure stem mechanical strength. This study provides preliminary evidence that suggests plants with high leaf trichome density have less stem mechanical strength, and those with low leaf trichome density have greater mechanical strength. Data generated from this study supports the idea that this may be a general and loose trend amongst plant families similar to …

Photosynthetic Advantage Of Invasive Species, Gabby Gurule-Small, Alis Sokolova, Patrick Stephens

Featured Research

Californians have greatly benefited from the introduction of plant and animal species necessary for food or other human pursuits; however, there are many other introduced species that can wreak havoc on the state’s environment and economy. Invasive species threaten the diversity and abundance of native species by both competing for resources and causing changes to the natural habitat. We hypothesize that invasive species will have higher photosynthetic and conductance rates which contribute to their success. Through their impacts on natural ecosystems, agricultural lands, and water delivery systems, invasive species may also negatively affect human health and possibly even the economy.

Is There A Correlation Between Water Potential And Mechanical Strength Of Stems Of Malosma Laurina?, William Chang, Lauren Price, Nicolas Pak

Featured Research

The purpose of this experiment was to see if there was a correlation between water potential and the stem mechanical strength of the Malosma laurina. This experiment was conducted with the use of a Scholander-Hammel pressure chamber to find water potential and the Instron 5500 to test the mechanical strength of the stems. After analysis of the data, there was no direct correlation between water potential and the mechanical strength of stems of Malosma laurina.

The Relationship Of Stomatal Conductnace To Mechanical Strength In Leaves Of Santa Monica Plants, Russell P. Mott, Steven R. Fleming, John R. Macbeth

Featured Research

The Santa Monica Mountains ecosystem has a high diversity of plants with different lifestyles that produce different physiological characteristics individual to all plants. Studies in Australia, another Mediterranean ecosystem, have shown that mechanical strength of leaves is relatable to soil stress. This experiment seeks to determine whether mechanical strengths of leaves correlate to stomatal conductance of leaves across different species in the Santa Monica Mountains. Four species of plants are tested for their stomatal conductance in the field, and the leaves are tested for tensile strength using Young’s Modulus for comparison across leaves. These data show that there was no …