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Biomedical Thrillers: Fiction Based In Fact, Or Just Fiction?, Emily F. Schmitt Lavin

Biology Faculty Proceedings, Presentations, Speeches, Lectures

No abstract provided.

A Preliminary Study Of The Vegetation Of Vernal Pools Of Acadia National Park, Maine, U.S.A, Brett Ciccotelli, Tanner B. Harris, Bruce Connery, Nishanta Rajakaruna

Biological Sciences

We conducted a preliminary floristic study of six vernal pools in Acadia National Park on Mount Desert Island, Maine. Plant species were recorded on three sampling dates from April to October, 2008. Sixty-five vascular plant species from 26 families were recorded. Of these, 27 are considered occasional or uncommon in Acadia National Park. Thirteen species are new reports for vernal pools in the northeastern United States. This represents the first published study of the vernal pool flora of Acadia National Park.

Stochastic Life-History Variation In Populations Of Western Ribbon Snakes (Thamnophis Proximus) In East Texas, Jeremy Chamberlain

Biology Theses

Understanding variation in life-history strategies can be important when determining the influence of an organism's environment on its natural history. Variation in strategies can play a significant role on the overall fitness and survival of an individual. Some environmental conditions may influence this variation more than others. In particular, stochastic environments, such as a floodplain, may have large impacts on life history strategies of organisms living within them. Floodplains are known to have high rates of extrinsic mortality. Theoretically this should shift life-history traits toward a fast-type strategy, with fast growth rates, high annual fecundity, and larger mean body-sizes. To …

Depletion Of Beclin-1 Due To Proteolytic Cleavage By Caspases In The Alzheimer's Disease Brain, Troy T. Rohn, Ellen Wirawan, Raquel J. Brown, Jordan R. Harris, Eliezer Masliah, Peter Vandenabeele

Biology Faculty Publications and Presentations

The Beclin-1 protein is essential for the initiation of autophagy and recent studies suggest this function may be compromised in Alzheimer’s disease (AD). In addition, in vitro studies have supported a loss of function of Beclin-1 due to proteolytic modification by caspases. In the present study we examined whether caspase-cleavage of Beclin-1 occurs in the AD brain by designing a site-directed caspase-cleavage antibody based upon a known cleavage site within the protein at position D149. We confirmed that Beclin-1 is an excellent substrate for caspase-3 and demonstrate cleavage led to the formation of a 35 kDa C-terminal fragment labeled by …

Sunday Driver/Jip3 Binds Kinesin Heavy Chain Directly And Enhances Its Motility, Faneng Sun, Chuanmei Zhu, Ram Dixit, Valeria Cavalli

Biology Faculty Research

Neuronal development, function and repair critically depend on axonal transport of vesicles and protein complexes, which is mediated in part by the molecular motor kinesin‐1. Adaptor proteins recruit kinesin‐1 to vesicles via direct association with kinesin heavy chain (KHC), the force‐generating component, or via the accessory light chain (KLC). Binding of adaptors to the motor is believed to engage the motor for microtubule‐based transport. We report that the adaptor protein Sunday Driver (syd, also known as JIP3 or JSAP1) interacts directly with KHC, in addition to and independently of its known interaction with KLC. Using an in vitro motility assay, …

Effects Of The Herbicide Atrazine On The Behavior Of The Checkered Gartersnake (Thamnophis Marcianus), Katie Chamberlain

Biology Theses

Atrazine is one of the most commonly used herbicides in the United States and one of the most popular weed-killers worldwide, being utilized in over 80 countries. Despite the effectiveness of atrazine, there has been growing concern over the potential harmful effects this chemical may have on non-target species exposed to this chemical. Few studies, however, have been performed on the effects of this chemical on reptiles, in particular snakes. This study examined the effects of environmentally relevant concentrations of atrazine on the foraging, antipredator, thermoregulatory, and courtship behaviors of the checkered gartersnake (Thamnophis marcianus). Effects of atrazine appeared negligible …

Mechanical Test Methods For Assessing Porcine Carotid And Uterine Artery Burst Pressure Following Ex Vivo Ultrasonic Ligature Seal And Transection, Carissa M. Krane, Margaret Pinnell, Courtney Gardner, Mercedes Thompson, James Coleman, Robert Wilkens

Biology Faculty Publications

A test method was developed to identify those variables important for assessing the performance of ultrasonic surgical devices in ex vivo ligature sealing of porcine carotid and uterine arteries. Ruggedness testing using a small sample size in pilot experiments was conducted using a newly developed test method in an effort to assess the usefulness of this methodology and to identify test variables that might warrant further testing. The development of this test method included the use of a custom-designed prototypic tension device for load-controlled ex vivo vessel stretching during saline perfusion and subsequent seal and transection of porcine arteries with …

Mathematical Modeling And Dynamical Analysis Of The Operation Of The Hypothalamus - Pituitary - Thyroid (Hpt) Axis In Autoimmune (Hashimoto's) Thyroiditis, Balamurugan Pandiyan

Dissertations (1934 -)

This thesis is a mathematical modeling study of the operation of the negative feedback control through the hypothalamus-pituitary- thyroid (HPT) axis in autoimmune (Hashimoto's) thyroiditis. Negative feedback control through the HPT axis is a mechanism in which the high levels of thyroid hormone; free thyroxine (FT4) in the blood inhibits the secretion of the pituitary hormone, thyroid stimulating hormone (TSH) into the blood. Similarly, the low levels of free thyroxine (FT4) sensed by the pituitary gland and then it secretes thyroid stimulating hormone (TSH) into the blood. Autoimmune (Hashimoto's) thyroiditis is a disease in which the immune system turns against …

Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia

Theses and Dissertations - UTB/UTPA

Non-native grasses can modify the soils they invade. This study investigated microbial variation among native and non-native grasses in the Lower Rio Grande Valley. We hypothesized that rhizospheres of non-native grasses would support a higher density of microorganisms; therefore microbial communities of invasive plants would exploit more carbon sources than those of native plants. A second hypothesis stated that Streptomyces bacteria from the rhizosphere of non-native grasses would be better competitors. Samples of grasses, and soil from their respective rhizospheres were obtained in Arroyo City, TX. Results indicated a higher bacterial colony density, total activity and number of substrates utilized …

Multistate Mark-Recapture Analysis Reveals No Effect Of Blood Sampling On Survival And Recapture Of Eastern Kingbirds (Tyrannus Tyrannus), Lucas J. Redmond, Michael T. Murphy

Biology Faculty Publications and Presentations

The experimentally supported and prevailing opinion is that blood sampling has few to no long-term effects on survival of birds when conducted properly, and blood sampling has become a vital addition to the toolbox of many ornithologists. However, many of the studies that concluded that blood sampling had negligible effects on birds used approaches that did not account for temporary emigration and probability of capture. To date, the only study to have done so found that blood sampling had a strong negative effect on survival. We conducted a mark–recapture analysis of 8 years of banding and bleeding data on Eastern …

Effects Of Training And Testosterone On Muscle-Fiber Types And Locomotor Performance In Male Six-Lined Racerunners (Aspidoscelis Sexlineata), Jennifer L. O'Conner, Lance D. Mcbrayer, Timothy E. Higham, Jerry F. Husak, Ignacio T. Moore, David C. Rostal

Biology: Faculty Publications

Testosterone (T) is thought to affect a variety of traits important for fitness, including coloration, the size of sexual ornaments, aggression, and locomotor performance. Here, we investigated the effects of experimentally elevated T and locomotor training on muscle physiology and running performance in a nonterritorial male lizard species (Aspidoscelis sexlineata). Additionally, several morphological attributes were quantified to examine other characters that are likely affected by T and/or a training regimen. Neither training alone nor training with T supplementation resulted in increased locomotor performance. Instead, we found that T and training resulted in a decrease in each of three …

Transcriptional Analysis Of Schistosoma Mansoni Treated With Sub-Lethal Doses Of The Anthelmintic Drug Praziquantel, Jarrett Hines-Kay

Biology ETDs

Schistosoma mansoni is one of the most common etiological agents responsible for the disease schistosomiasis. More than 200 million people suffer from this disease making it the most severe tropical disease after malaria in terms of morbidity. Praziquantel (PZQ) is the treatment of choice for schistosomiasis and has been used almost exclusively to treat the disease since the 1970s. However, while the drug is lethal for sexually mature schistosomes, it is ineffective against juveniles. Thus, while morbidity can be eased, a cure is difficult to achieve. As a result there is an urgent need to develop a new generation of …

Mammalian Diversification Across The Holarctic: Spatiotemporal Evolution In Response To Environmental Change, Andrew G. Hope

Biology ETDs

The primary focus in this dissertation is on the processes of environmental change that drive evolution. We are currently witnessing unparalleled changes in climate and associated changes in biotic communities. With a growing understanding that climate and habitat change, coupled with natural variability, will have an increased influence on biota into the future, it is our responsibility to learn how best to manage and conserve the Earths natural resources. Among other things, this will require a firmer understanding of biodiversity, life histories, evolutionary relationships among species, and community dynamics over multiple species. One method of understanding how species will respond …

Allometric Scaling And Metabolic Ecology Of Microorganisms And Major Evolutionary Transitions, Jordan G. Okie

Biology ETDs

My dissertation centers around investigating big-picture questions related to understanding the consequences of metabolism and energetics on the evolution, ecology, and physiology of life. The evolutionary transitions from prokaryotes to unicellular eukaryotes to multicellular organisms were accompanied by major innovations in metabolic design. In my first chapter, I show that the scaling of metabolic rate, population growth rate, and production efficiency with body size have changed across these transitions. Metabolic rate scales with body mass superlinearly in prokaryotes, linearly in protists, and sublinearly in metazoans, so Kleibers 3/4 power scaling law does not apply universally across organisms. This means that …

Juvenile Hormone Regulates Extreme Mandible Growth In Male Stag Beetles, Hiroki Gotoh, Richard Cornette, Shigeyuki Koshikawa, Yasukazu Okada, Laura Corley Lavine, Douglas J. Emlen, Toru Miura

Biological Sciences Faculty Publications

The morphological diversity of insects is one of the most striking phenomena in biology. Evolutionary modifications to the relative sizes of body parts, including the evolution of traits with exaggerated proportions, are responsible for a vast range of body forms. Remarkable examples of an insect trait with exaggerated proportions are the mandibular weapons of stag beetles. Male stag beetles possess extremely enlarged mandibles which they use in combat with rival males over females. As with other sexually selected traits, stag beetle mandibles vary widely in size among males, and this variable growth results from differential larval nutrition. However, the mechanisms …

Isopods Failed To Acclimate Their Thermal Sensitivity Of Locomotor Performance During Predictable Or Stochastic Cooling, Matthew S. Schuler, Brandon S. Cooper, Jonathan J. Storm, Michael W. Sears, Michael J. Angilletta Jr

Biology Faculty Research and Scholarship

Most organisms experience environments that vary continuously over time, yet researchers generally study phenotypic responses to abrupt and sustained changes in environmental conditions. Gradual environmental changes, whether predictable or stochastic, might affect organisms differently than do abrupt changes. To explore this possibility, we exposed terrestrial isopods (Porcellio scaber) collected from a highly seasonal environment to four thermal treatments: (1) a constant 20 degrees C; (2) a constant 10 degrees C; (3) a steady decline from 20 degrees to 10 degrees C; and (4) a stochastic decline from 20 degrees to 10 degrees C that mimicked natural conditions during autumn. After …

Cooperative And Antagonistic Contributions Of Two Heterochromatin Proteins To Transcriptional Regulation Of The Drosophila Sex Determination Decision, Hui Li, Janel Rodriguez, Youngdong Yoo, Momin Mohammed Shareef, Ramakrishna Badugu, Jamila I. Horabin, Rebecca Kellum

Biology Faculty Publications

Eukaryotic nuclei contain regions of differentially staining chromatin (heterochromatin), which remain condensed throughout the cell cycle and are largely transcriptionally silent. RNAi knockdown of the highly conserved heterochromatin protein HP1 in Drosophila was previously shown to preferentially reduce male viability. Here we report a similar phenotype for the telomeric partner of HP1, HOAP, and roles for both proteins in regulating the Drosophila sex determination pathway. Specifically, these proteins regulate the critical decision in this pathway, firing of the establishment promoter of the masterswitch gene, Sex-lethal (Sxl). Female-specific activation of this promoter, Sxl(Pe), is essential to females, as it provides SXL …

Yeast Bax Inhibitor, Bxi1p, Is An Er-Localized Protein That Links The Unfolded Protein Response And Programmed Cell Death In Saccharomyces Cerevisiae, Nicanor Austriaco, James Cebulski, Joshua Malouin, Nathan Pinches, Vincent Cascio

Biology Faculty Publications

Bax inhibitor-1 (BI-1) is an anti-apoptotic gene whose expression is upregulated in a wide range of human cancers. Studies in both mammalian and plant cells suggest that the BI-1 protein resides in the endoplasmic reticulum and is involved in the unfolded protein response (UPR) that is triggered by ER stress. It is thought to act via a mechanism involving altered calcium dynamics. In this paper, we provide evidence that the Saccharomyces cerevisiae protein encoded by the open reading frame, YNL305C, is a bona fide homolog for BI-1. First, we confirm that yeast cells from two different strain backgrounds lacking YNL305C, …

Importance Of Behavior And Morphological Traits For Controlling Body Temperature In Littorinid Snails, Luke Miller, Mark Denny

Faculty Publications, Biological Sciences

For organisms living in the intertidal zone, temperature is an important selective agent that can shape species distributions and drive phenotypic variation among populations. Littorinid snails, which occupy the upper limits of rocky shores and estuaries worldwide, often experience extreme high temperatures and prolonged aerial emersion during low tides, yet their robust physiology—coupled with morphological and behavioral traits—permits these gastropods to persist and exert strong grazing control over algal communities. We use a mechanistic heat-budget model to compare the effects of behavioral and morphological traits on the body temperatures of five species of littorinid snails under natural weather conditions. Model …

Camera Study For Mammalian Carnivore Presence Across Seasons In Montana De Oro State Park, San Luis Obispo County, Ca, Samuel R. Young

Natural Resources Management and Environmental Sciences

Montana de Oro (MDO) is one of the largest state parks in California. Little is known however about its wildlife or their habits. Large predators such as mountain lion (Puma concolor) and black bear (Ursus americanus), and non–native species such as red fox (Vulpes vulpes) and feral pig (Sus scropha) are of management concern because of their potentially dramatic ecological roles. Cameras were deployed at 5 sites along the Coon Creek hiking trail in spring (May 3–June 7), summer (July 15–August 19), and fall (October 10–November 23) sessions with the goal of …

Isopods Failed To Acclimate Their Thermal Sensitivity Of Locomotor Performance During Predictable Or Stochastic Cooling, Michael W. Sears, Matthew S. Schuler, Brandon S. Cooper, Jonathan J. Storm, Michael J. Angilletta

Publications

Most organisms experience environments that vary continuously over time, yet researchers generally study phenotypic responses to abrupt and sustained changes in environmental conditions. Gradual environmental changes, whether predictable or stochastic, might affect organisms differently than do abrupt changes. To explore this possibility, we exposed terrestrial isopods (Porcellio scaber) collected from a highly seasonal environment to four thermal treatments: (1) a constant 20°C; (2) a constant 10°C; (3) a steady decline from 20° to 10°C; and (4) a stochastic decline from 20° to 10°C that mimicked natural conditions during autumn. After 45 days, we measured thermal sensitivities of running …

The Effects Of Neonatal Handling On Adrenocortical Responsiveness, Morphological Development And Corticosterone Binding Globulin In Nestling American Kestrels (Falco Sparverius), Buddy A. Whitman, Creagh W. Breuner, Alfred M. Dufty

Biology Faculty Publications and Presentations

Early developmental experiences play an important role in development of the adult phenotype. We investigated the effects of neonatal handling on the hypothalamic-pituitary-adrenal axis in a free-living avian species, the American kestrel (Falco sparverius). In the handled group (H), kestrel chicks were handled for 15 min/day from hatching until 26 days of age, after which time blood samples were collected for analysis of adrenal responsiveness and corticosterone binding globulin (CBG) levels. The non-handled control group (NH) was left undisturbed until 26 days of age when blood samples were collected and analyzed as above. Handled and NH kestrels did not differ …

Life History Benefits Of Residency In A Partially Migrating Pond-Breeding Amphibian, Kristine L. Grayson, Larissa L. Bailey, Henry M. Wilbur

Biology Faculty Publications

Species with partial migration, where a portion of a population migrates and the other remains residential, provide the opportunity to evaluate conditions for migration and test mechanisms influencing migratory decisions. We conducted a five-year study of two populations of red-spotted newts (Notophthalmus viridescens), composed of individuals that either remain as residents in the breeding pond over the winter or migrate to the terrestrial habitat. We used multistate mark-recapture methods to (1) test for differences in survival probability between migrants and residents, (2) determine if migrants breed every year or skip opportunities for reproduction, and (3) estimate the frequency …

Factors Affecting Phytoplankton Biodiversity And Toxin Production, Tracey Magrann

Loma Linda University Electronic Theses, Dissertations & Projects

This dissertation reports a survey of water quality, algal biodiversity, and toxin production in Southern California lakes, ponds, bays, and lagoons along the California coastline, in five counties from Santa Barbara to San Diego. Samples were analyzed for pH, electrical conductivity, total dissolved solids, dissolved oxygen, alkalinity, chlorophyll–a, total phosphorous, phosphate, total dissolved phosphorous, dissolved organic and inorganic phosphorous, particulate phosphorous, total nitrogen, total dissolved nitrogen, dissolved organic and inorganic nitrogen, nitrate, nitrite, and ammonium. Algal assays were conducted for phytoplankton identification and numbers, and indices of biodiversity (richness and evenness) were calculated to ascertain relationships between nutrients and algal …

Effects Of Heavy Metal Pollution On The Loggerhead Sea Turtle, Ashley L. Register

Loma Linda University Electronic Theses, Dissertations & Projects

Historically, heavy metal research on sea turtles has been focused on deceased specimens, limiting the ability to determine if the concentrations of heavy metals affected the health of the individuals. More recently, the collection and analysis of blood samples from live turtles has enabled the researcher to investigate the potential health implications of observed metal concentrations. In this thesis, I present two original studies on the blood concentrations of essential and non-essential heavy metals and their potential physiological correlates on the endangered loggerhead sea turtle (Caretta caretta). This work reflects analysis of archived samples collected in 2008 off the southeastern …

Behavioral Ecology, Taxonomy, And Conservation Genetics Of The Bahama Oriole (Icterus Northropi), Melissa R. Price

Loma Linda University Electronic Theses, Dissertations & Projects

In this dissertation, I examined the Bahama Oriole (Icterus northropi) at multiple scales, with the aim of developing a sound management plan for this critically endangered bird. In the first of five studies, I measured plumage variation among four allopatric populations of the former Icterus dominicensis complex in the Caribbean. Diagnosable plumage differences among populations contributed to the subsequent elevation of each of these populations (including northropi) to species status. In the second study, I examined molecular variation in subpopulations of 1. northropi on North Andros, Mangrove Cay, and South Andros, The Bahamas. I identified several patterns of genetic variation …

The Conservation And Habitat Ecology Of Antillean Manatees (Trichechus Manatus Manatus) In The Drowned Cayes Area Of Belize, Central America, Katherine Spencer Lacommare

Graduate Doctoral Dissertations

The Drowned Cayes area of Belize, Central America is regionally important for the conservation of Antillean manatees in the Caribbean (Lefebvre et al. 2001; Quintana-Rizzo & Reynolds 2008). These islands are increasingly threatened by human activities such as tourism, development and population growth. The objective of this dissertation is to evaluate manatee habitat use and status in this area. The 5 specific objectives are to examine manatee (1) distribution in the Drowned Cayes, (2) use of seagrass beds and forage selection, (3) resting habitat use and selection (4) response to disturbance, and (5) trends in abundance and to suggest a …

Immunolocalization Of Influenza A Virus And Markers Of Inflammation In The Human Parkinson’S Disease Brain, Troy T. Rohn, Lindsey W. Catlin

Biology Faculty Publications and Presentations

Although much is known regarding the molecular mechanisms leading to neuronal cell loss in Parkinson’s disease (PD), the initiating event has not been identified. Prevailing theories including a chemical insult or infectious agent have been postulated as possible triggers, leading to neuroinflammation. We present immunohistochemical data indicating the presence of influenza A virus within the substantia nigra pars compacta (SNpc) from postmortem PD brain sections. Influenza A virus labeling was identified within neuromelanin granules as well as on tissue macrophages in the SNpc. Further supporting a role for neuroinflammation in PD was the identification of T-lymphocytes that colocalized with an …

Homoplastic Microinversions And The Avian Tree Of Life, E. L. Braun, R T. Kimball, K. L. Han, N. R. Luhasz-Velez, A. J. Bonilla, Jena L. Chojnowski, J. V. Smith, R. C. Bowie, M. J. Braun, S. J. Hackett, J. Harshman, C. J. Huddleston, B. D. Marks, W. S. Moore, S. Reddy, F. H. Sheldon, C. C. Witt, T. Yuri

Natural Sciences Faculty Publications

BACKGROUND:

Microinversions are cytologically undetectable inversions of DNA sequences that accumulate slowly in genomes. Like many other rare genomic changes (RGCs), microinversions are thought to be virtually homoplasy-free evolutionary characters, suggesting that they may be very useful for difficult phylogenetic problems such as the avian tree of life. However, few detailed surveys of these genomic rearrangements have been conducted, making it difficult to assess this hypothesis or understand the impact of microinversions upon genome evolution.

RESULTS:

We surveyed non-coding sequence data from a recent avian phylogenetic study and found substantially more microinversions than expected based upon prior information about vertebrate …

Range-Expanding Populations Of A Globally Introduced Weed Experience Negative Plant-Soil Feedbacks, Krikor Andonian, José L. Hierro, Liana Khetsuriani, Pablo Becerra, Grigor Janoyan, Diego Villarreal, Lohengrin Cavieres, Laurel R. Fox, Ragan M. Callaway

Biological Sciences Faculty Publications

Background: Biological invasions are fundamentally biogeographic processes that occur over large spatial scales. Interactions with soil microbes can have strong impacts on plant invasions, but how these interactions vary among areas where introduced species are highly invasive vs. naturalized is still unknown. In this study, we examined biogeographic variation in plant-soil microbe interactions of a globally invasive weed, Centaurea solstitialis (yellow starthistle). We addressed the following questions (1) Is Centaurea released from natural enemy pressure from soil microbes in introduced regions? and (2) Is variation in plant-soil feedbacks associated with variation in Centaurea's invasive success? Methodology/Principal Findings: We conducted greenhouse …