Integrative Biology Commons^™

Effects Of Nutrient Supplementation On Host-Pathogen Dynamics Of The Amphibian Chytrid Fungus: A Community Approach, Julia C. Buck, Jason R. Rohr, Andrew R. Blaustein

Integrative Biology Faculty and Staff Publications

1. Anthropogenic stressors may influence hosts and their pathogens directly or may alter host–pathogen dynamics indirectly through interactions with other species. For example, in aquatic ecosystems, eutrophication may be associated with increased or decreased disease risk. Conversely, pathogens can influence community structure and function and are increasingly recognised as important members of the ecological communities in which they exist.
2. In outdoor mesocosms, we experimentally manipulated nutrients (nitrogen and phosphorus) and the presence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), and examined the effects on Bd abundance on larval amphibian hosts (Pseudacris regilla: Hylidae), amphibian traits and community dynamics. We …

An Experiment In Graduate Education: A Marine Science Adventure Across The Indian Ocean, Vicki Buchsbaum Pearse, John C. Ogden, Sharon J. Proctor

Integrative Biology Faculty and Staff Publications

In the fall of 1964, Stanford University’s R/V Te Vega Cruise 5 crossed the equatorial Indian Ocean from Mombasa to Singapore, one of many ships participating in the International Indian Ocean Expedition. The cruise achieved two goals: (1) it provided hands-on oceanography training for graduate students in marine sciences, and (2) it documented the deep scattering layers of the Indian Ocean, only poorly known at the time. Taking place on the other side of the globe from the United States, the cruise also exposed students to cultural and personal experiences that shaped their lives and professions. It demonstrated the importance …

Spatial Spread Of The West Africa Ebola Epidemic, Andrew M. Kramer, J. Tomlin Pulliam, Laura W. Alexander, Andrew W. Park, Pejman Rohani, John M. Drake

Integrative Biology Faculty and Staff Publications

Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternative epidemic paths. We compared multiple candidate models to characterize the spatial network over which the 2013–2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia …

Ordination Obscures The Influence Of Environment On Plankton Metacommunity Structure, Tad A. Dallas, Andrew M. Kramer, Marcus Zokan, John M. Drake

Integrative Biology Faculty and Staff Publications

The composition of plankton communities in individual habitats is often influenced by environmental conditions like pH or hydroperiod. At larger scales, environmental gradients can influence community structure across interconnected local communities. Detecting the role of environmental and spatial factors on metacommunity structure depends on the ordering of sites and species prior to analysis. We investigated this ordination in two wetland metacommunities; a well-sampled, hyper-diverse zooplankton metacommunity, and a Central American phytoplankton metacommunity. We calculated coherence, turnover, and boundary clumping to classify the structure of the metacommunity, and we propose a statistic that responds to variation in both coherence and turnover. …

Mathematical Models Are A Powerful Method To Understand And Control The Spread Of Huanglongbing, Rachel A. Taylor, Erin Mordecai, Christopher A. Gilligan, Jason R. Rohr, Leah R. Johnson

Integrative Biology Faculty and Staff Publications

Huanglongbing, or citrus greening, is a global citrus disease occurring in almost all citrus growing regions and causing substantial economic burdens to individual growers, citrus industries and governments. Successful management strategies to reduce disease burden are desperately needed but with so many possible interventions and combinations thereof, it is difficult to know which are worthwhile or cost-effective. We review how mathematical models have yielded useful insights into controlling disease spread for other vector-borne plant diseases, and the small number of mathematical models of Huanglongbing. We adapt a malaria model to Huanglongbing, by including temperature-dependent psyllid traits and economic costs, to …

The Pros And Cons Of Ecological Risk Assessment Based On Data From Different Levels Of Biological Organization, Jason R. Rohr, Christopher J. Salice, Roger M. Nisbet

Integrative Biology Faculty and Staff Publications

Ecological risk assessment (ERA) is the process used to evaluate the safety of manufactured chemicals to the environment. Here we review the pros and cons of ERA across levels of biological organization, including suborganismal (e.g., biomarkers), individual, population, community, ecosystem and landscapes levels. Our review revealed that level of biological organization is often related negatively with ease at assessing cause-effect relationships, ease of high-throughput screening of large numbers of chemicals (it is especially easier for suborganismal endpoints), and uncertainty of the ERA because low levels of biological organization tend to have a large distance between their measurement (what is quantified) …

The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce, John M. Drake

Integrative Biology Faculty and Staff Publications

Bivalves process large volumes of water, leading to their accumulation of bacteria, including potential human pathogens (e.g., vibrios). These bacteria are captured at low efficiencies when freely suspended in the water column, but they also attach to marine aggregates, which are captured with near 100% efficiency. For this reason, and because they are often enriched with heterotrophic bacteria, marine aggregates have been hypothesized to function as important transporters of bacteria into bivalves. The relative contribution of aggregates and unattached bacteria to the accumulation of these cells, however, is unknown. We developed an agent-based model to simulate accumulation of vibrio-type bacteria …

Seasonal Dynamics And Micro-Climatic Preference Of Two Alpine Endemic Hypogean Beetles, Stefano Mammola, Elena Piano, Pier Mauro Giachino, Marco Isaia

International Journal of Speleology

Hypogean beetles generally live in stable environments, characterized by constant temperature and high relative humidity. Changes in the underground microclimatic conditions generally induce local migrations of the beetles through the hypogean environment in search of suitable microhabitats. We studied the seasonal dynamics and the micro-climatic preference of two Alpine endemic hypogean beetles - Sphodropsis ghilianii (Coleoptera, Carabidae) and Dellabeffaella roccae (Coleoptera, Cholevidae) - in the hypogean complex of Pugnetto (Graian Alps, Italy). We surveyed the two species for one year, using baited pitfall traps and measuring temperature and humidity along the two main caves. We used logistic regression mixed models …

An Investigation Of The Effects Of Increased Tidal Inundation, Competition, And Facilitation On Salt Marsh Systems, Jennifer A. Hyder

USF Tampa Graduate Theses and Dissertations

The low-lying topographic nature of salt marshes makes plants in these communities particularly vulnerable to increased salinity and inundation exposure associated with sea level rise. Both increased salinity and inundation have been cited as major causes of reduced plant performance and survival in marsh and areas fringing marsh. In addition to limitations imposed by physical stress, interspecific interactions have also been shown to mediate the performance and survival of salt marsh and salt marsh fringing species. The Stress Gradient Hypothesis (SGH) postulates that species interactions shift from competitive to facilitative as stress levels increase and predicts that (a) the frequency …

Status Of A Translocated Florida Sand Skink Population After Six Years: Establishing And Evaluating Criteria For Success, Adam Ryan Emerick

USF Tampa Graduate Theses and Dissertations

The translocation of organisms is becoming a frequently used tool in conservation biology. There are, however, a disproportionate number of unsuccessful attempts translocating populations of herpetofauna. Logistical and temporal limits of monitoring, combined with ambiguous metrics concerning "success," have led to few advances regarding reptile translocations. Successfully established and persistent populations are those in which both the founding population and subsequent generations show consistent or positive levels of survival and reproduction. A small population of the threatened Florida Sand Skink (Plestiodon reynoldsi) was translocated in 2007. Data collected from 2007 to 2009 confirmed survival and reproduction among the founding individuals, …

Adaptive Plasticity And Epigenetic Variation In Response To Warming In An Alpine Plant, Adrienne B. Nicotra, Deborah L. Segal, Gemma L. Hoyle, Aaron W. Schrey, Koen J. Verhoeven, Christina L. Richards

Integrative Biology Faculty and Staff Publications

Environmentally induced phenotypic plasticity may be a critical component of response to changing environments. We examined local differentiation and adaptive phenotypic plasticity in response to elevated temperature in half-sib lines collected across an elevation gradient for the alpine herb, Wahlenbergia ceracea. Using Amplified Fragment Length Polymorphism (AFLP), we found low but significant genetic differentiation between low- and high-elevation seedlings, and seedlings originating from low elevations grew faster and showed stronger temperature responses (more plasticity) than those from medium and high elevations. Furthermore, plasticity was more often adaptive for plants of low-elevation origin and maladaptive for plants of high elevation. With …

Ebola Cases And Health System Demand In Liberia, John M. Drake, Rajreni B. Kaul, Laura W. Alexander, Suzanne M. O’Regan, Andrew M. Kramer, J. Tomlin Pulliam, Matthew J. Ferrari, Andrew W. Park

Integrative Biology Faculty and Staff Publications

In 2014, a major epidemic of human Ebola virus disease emerged in West Africa, where human-to-human transmission has now been sustained for greater than 12 months. In the summer of 2014, there was great uncertainty about the answers to several key policy questions concerning the path to containment. What is the relative importance of nosocomial transmission compared with community-acquired infection? How much must hospital capacity increase to provide care for the anticipated patient burden? To which interventions will Ebola transmission be most responsive? What must be done to achieve containment? In recent years, epidemic models have been used to guide …

Immigration Can Destabilize Tri-Trophic Interactions: Implications For Conservation Of Top Predators, Kevin L. S. Drury, Jesse D. Suter, Jacob B. Rendall, Andrew M. Kramer, John M. Drake

Integrative Biology Faculty and Staff Publications

Top predators often have large home ranges and thus are especially vulnerable to habitat loss and fragmentation. Increasing connectance among habitat patches is therefore a common conservation strategy, based in part on models showing that increased migration between subpopulations can reduce vulnerability arising from population isolation. Although three-dimensional models are appropriate for exploring consequences to top predators, the effects of immigration on tri-trophic interactions have rarely been considered. To explore the effects of immigration on the equilibrium abundances of top predators, we studied the effects of immigration in the three-dimensional Rosenzweig-MacArthur model. To investigate the stability of the top predator …

Ebola Cases And Health System Demand In Liberia, John M. Drake, Rajreni B. Kaul, Laura W. Alexander, Suzanne M. O’Regan, Andrew M. Kramer, J. Tomlin Pulliam, Matthew J. Ferrari, Andrew W. Park

Integrative Biology Faculty and Staff Publications

In 2014, a major epidemic of human Ebola virus disease emerged in West Africa, where human-to-human transmission has now been sustained for greater than 12 months. In the summer of 2014, there was great uncertainty about the answers to several key policy questions concerning the path to containment. What is the relative importance of nosocomial transmission compared with community-acquired infection? How much must hospital capacity increase to provide care for the anticipated patient burden? To which interventions will Ebola transmission be most responsive? What must be done to achieve containment? In recent years, epidemic models have been used to guide …

Impacts Of Agrochemical Pollution On Aquatic Communities And Human Disease, Neal T. Halstead

USF Tampa Graduate Theses and Dissertations

The global human population is expected to exceed 9 billion individuals by 2050, putting greater strain on the natural resources needed to sustain such a population. To feed this many people, some expect agricultural production will have to double and agrochemical use will have to increase anywhere from two- to five-fold relative to the turn of the century. Although industrial agriculture has provided many benefits to society, it has caused declines in biodiversity, both directly (e.g., through conversion of habitat) and indirectly (e.g., through contamination of adjacent natural habitats). Agricultural activity has also been linked to increased prevalence and intensity …

Comparison Of Gastropod Assemblages From Natural And Phosphate Mine Lakes Of Central Florida, William A. Mailand

USF Tampa Graduate Theses and Dissertations

Investigations were made examining the relationships between gastropod species richness and abundance across 20 phosphate and 20 natural lakes in Central Florida. In additional to lake category, age of phosphate lakes was used to determine if phosphate lakes ever approximate natural lakes. Additional physical, chemical, and biological parameters, including chlorophyll a, Ca, secchi, phosphorous, conductance, fish predation, and recreational lake use were investigated in order to determine if they affected gastropods with lake age. Comparisons were also made between gastropod species richness and average abundance and two groups of dominant vegetation categories: Panicum, a structurally complex macrophyte, and Typha …

Functional Morphology And Feeding Mechanics Of Billfishes, María Laura Habegger

USF Tampa Graduate Theses and Dissertations

Billfishes (marlins, spearfishes, sailfishes and swordfish) are one of the fastest and largest marine apex predators, and perhaps their most recognizable attribute is their bill or rostrum. The proposed function for this novel structure has ranged from hydrodynamic enhancement to defensive weaponry. However, the most supported hypothesis for its function has been linked to feeding. Billfishes have been observed to subdue their prey with their rostrum, either stunning or cutting them into pieces before ingestion. Due to their large body sizes and pelagic lifestyles a thorough investigation of the function of this structure has been logistically challenging. The goal of …

Influences Of Yard Management Intensity On Urban Soil Biogeochemistry, Viviana Penuela Useche

USF Tampa Graduate Theses and Dissertations

Soils are critical to ecosystem function as they provide essential nutrients for primary producers, habitat and organic energy for decomposers, and storage of organic matter. Irrigation with reclaimed water is an increasingly popular water conservation strategy; yet its high salinity and nutrient content potentially affect soil properties. In this study, set in a residential neighborhood of Tampa (U.S.). I tested whether there are distinct lawn system management strategies characterized by systematic differences in reclaimed water usage and irrigation and fertilization practices. I then investigated whether soil biogeochemistry responds to lawn system management strategy.

My results indicated that amendment strategy, which …

Nitrogen Inputs And Losses In Response To Chronic Co2 Exposure In A Subtropical Oak Woodland, B. A. Hungate, B. D. Duval, P. Dijkstra, D. W. Johnson, M. E. Ketterer, Peter Stiling, W. Cheng, J. Millman, A. Hartley, D. B. Stover

Integrative Biology Faculty and Staff Publications

Rising atmospheric CO₂ concentrations may alter the nitrogen (N) content of ecosystems by changing N inputs and N losses, but responses vary in field experiments, possibly because multiple mechanisms are at play. We measured N fixation and N losses in a subtropical oak woodland exposed to 11 years of elevated atmospheric CO₂ concentrations. We also explored the role of herbivory, carbon limitation, and competition for light or nutrients in shaping the response of N fixation to elevated CO₂. Elevated CO₂ did not significantly alter gaseous N losses, but lower recovery and deeper distribution in the …

Assessing The In Situ Fertilization Status Of Two Marine Copepod Species, Temora Longicornis And Eurytemora Herdmani; How Common Are Unfertilized Eggs In Nature?, Rachel S. Lasley-Rasher, Andrew M. Kramer, Victoria Burdett-Coutts, Jeannette Yen

Integrative Biology Faculty and Staff Publications

We utilized an egg staining technique to measure the in situ fertilization success of two marine copepod species, Temora longicornis and Eurytemora herdmani from May to October 2008 in coastal Maine and correlated fertilization success with environmental conditions in their habitat. T. longicornis is a free spawning species that releases eggs into the ambient seawater after mating. In contrast, E. herdmani carries eggs in an egg sac until they hatch. The proportion of fertilized eggs within E. herdmani egg sacs was significantly higher than the freely spawned clutches of T. longicornis. This may be a result of the asymmetrical costs …

Time To Competitive Exclusion, Andrew M. Kramer, John M. Drake

Integrative Biology Faculty and Staff Publications

A predictive theory of population extinction for natural populations requires integrating the effects of stochasticity with the interactions engaged in with populations of other species. The theory of competitive exclusion predicts that inferior competitors for a limiting resource will be driven to extinction, but the effects of resource competition on time to extinction have not been examined. We studied a stochastic version of Tilman's resource competition model to examine two species competition-driven extinction. Simulations showed that competitive imbalance, population size and demographic rates of the “inferior” competitor were the most important determinants of mean extinction time, while factors including resource …

Blood-Brain Barrier Alterations Provide Evidence Of Subacute Diaschisis In An Ischemic Stroke Rat Model, Svitlana Garbuzova-Davis, Maria C. O. Rodrigues, Diana G. Hernandez-Ontiveros, Naoki Tajiri, Aric Frisna-Deyo, Sean M. Boffeli, Jerry V. Abraham, Mibel Pabon, Andrew Wagner, Hiroto Ishikawa, Kazutaka Shinozuka, Edward M. Haller, Paul Sanberg, Yuji Kaneko, Cesario Borlongan

Integrative Biology Faculty and Staff Publications

Background: Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB) competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas.

Methodology/Principal Findings: In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO), significant BBB alterations characterized by large Evans Blue (EB) parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, …

Iron Modulates Cell Survival In A Ras- And Mapk-Dependent Manner In Ovarian Cells, K. A. Bauckman, Edward M. Haller, I. Flores, M. Nanjundan

Integrative Biology Faculty and Staff Publications

Ovarian cancer is a leading cause of cancer death in women in the United States. While the majority of ovarian cancers are serous, some rarer subtypes (i.e. clear cell) are often associated with endometriosis, a benign gynecological disease. Iron is rich in the cyst fluid of endometriosis-associated ovarian cancers and induces persistent oxidative stress. The role of iron, an essential nutrient involved in multiple cellular functions, in normal ovarian cell survival and ovarian cancer remains unclear. Iron, presented as ferric ammonium citrate (FAC), dramatically inhibits cell survival in ovarian cancer cell types associated with Ras mutations, while it is without …

Bacterial Colonization And Extinction On Marine Aggregates: Stochastic Model Of Species Presence And Abundance, Andrew M. Kramer, M. Maille Lyons, Fred C. Dobbs, John M. Drake

Integrative Biology Faculty and Staff Publications

Organic aggregates provide a favorable habitat for aquatic microbes, are efficiently filtered by shellfish, and may play a major role in the dynamics of aquatic pathogens. Quantifying this role requires understanding how pathogen abundance in the water and aggregate size interact to determine the presence and abundance of pathogen cells on individual aggregates. We build upon current understanding of the dynamics of bacteria and bacterial grazers on aggregates to develop a model for the dynamics of a bacterial pathogen species. The model accounts for the importance of stochasticity and the balance between colonization and extinction. Simulation results suggest that while …

Mitochondrial Dna Assessment Of The Phylogeography Of The Gopher Tortoise, Joshua R. Ennen, Brian R. Kreiser, Carl P. Qualls, Daniel Gaillard, Matthew Aresco, Roger Birkhead, Tracey Tuberville, Earl D. Mccoy, Henry R. Mushinsky, Thomas W. "Bill" Hentges, Aaron W. Schrey

Integrative Biology Faculty and Staff Publications

Identifying geographic barriers that define genetic structure within a species is crucial in formulating an effective conservation plan. The identification of appropriate management units is critical for the protection and recovery of the gopher tortoise Gopherus polyphemus, which have declined across their entire range. Previous molecular work at various spatial scales has identified distinct population assemblages of the gopher tortoise. The goal of this study was to assess the genetic structure in gopher tortoises through a more complete sampling of the federally listed as threatened portion of the range and evaluate the extent of genetic isolation imposed by several …

Demasculinization And Feminization Of Male Gonads By Atrazine: Consistent Effects Across Vertebrate Classes, Krista A. Mccoy

Integrative Biology Faculty and Staff Publications

Atrazine is the most commonly detected pesticide contaminant of ground water, surface water, and precipitation. Atrazine is also an endocrine disruptor that, among other effects, alters male reproductive tissues when animals are exposed during development. Here, we apply the nine so-called “Hill criteria” (Strength, Consistency, Specificity, Temporality, Biological Gradient, Plausibility, Coherence, Experiment, and Analogy) for establishing cause–effect relationships to examine the evidence for atrazine as an endocrine disruptor that demasculinizes and feminizes the gonads of male vertebrates. We present experimental evidence that the effects of atrazine on male development are consistent across all vertebrate classes examined and we present a …

Blood-Brain Barrier Impairment In An Animal Model Of Mps Iii B, Svitlana N. Garbuzova-Davis, Michael Louis, Edward M. Haller, Hiranya M. Derasari, Ashley E. Rawls, Paul R. Sanberg

Integrative Biology Faculty and Staff Publications

Background: Sanfilippo syndrome type B (MPS III B) is caused by a deficiency of α-N-acetylglucosaminidase enzyme, leading to accumulation of heparan sulfate within lysosomes and eventual progressive cerebral and systemic multiple organ abnormalities. However, little is known about the competence of the blood-brain barrier (BBB) in MPS III B. BBB dysfunction in this devastating disorder could contribute to neuropathological disease manifestations.

Methodology/Principal Findings: In the present study, we investigated structural (electron microscope) and functional (vascular leakage) integrity of the BBB in a mouse model of MPS III B at different stages of disease, focusing on brain structures known to experience …

Evidence Of Compromised Blood-Spinal Cord Barrier In Early And Late Symptomatic Sod1 Mice Modeling Als, Svitlana N. Garbuzova-Davis, Samuel Saporta, Edward M. Haller, Irina Kolomey, Steven P. Bennett, Huntington Potter, Paul R. Sanberg

Integrative Biology Faculty and Staff Publications

Background: The blood-brain barrier (BBB), blood-spinal cord barrier (BSCB), and blood-cerebrospinal fluid barrier (BCSFB) control cerebral/spinal cord homeostasis by selective transport of molecules and cells from the systemic compartment. In the spinal cord and brain of both ALS patients and animal models, infiltration of T-cell lymphocytes, monocyte-derived macrophages and dendritic cells, and IgG deposits have been observed that may have a critical role in motor neuron damage. Additionally, increased levels of albumin and IgG have been found in the cerebrospinal fluid in ALS patients. These findings suggest altered barrier permeability in ALS. Recently, we showed disruption of the BBB and …

Assessment Of Biogeochemical Deposits In Landfill Drainage Systems, Audrey D. Levine, Valerie J. Harwood, Antonio J. Cardoso, Lisa R. Rhea, Bina S. Nayak, Barbara M. Dodge, Mindy L. Decker, George Dzama, Lawrence Jones, Edward Haller

Integrative Biology Faculty and Staff Publications

Design, operation, and closure practices for Class I municipal solid waste (MSW) landfills are based on RCRA Subtitle D requirements for control of leachates and gases generated during the life of the landfill. Because leachate is generated as a result of water percolating through the landfill and waste consolidation, it contains dissolved and suspended materials that reflect the characteristics of the material it contacts. Over the past two decades significant changes have occurred in the characteristics of the waste streams that are disposed in landfills. In addition, many Florida municipalities have implemented Waste-to-Energy (WTE) systems. The WTE ash is either …

In Situ Of Interferon On Human Glioma Protein Kinase C-Α And -Β Ultrastructural Localization, Mildred Acevedo-Duncan, John Collins, Ruonana Zhang, Edward M. Haller, Charles E. Chalfant, Denise R. Cooper

Integrative Biology Faculty and Staff Publications

Transmission electron microscopy was used to determine how immunogold labeling of PKC-alpha or -beta is modulated by the antitumor drug IFN (HuIFN alpha-2b) in the cytoplasm, membrane structures, and nucleus of rapidly dividing and confluent human glioma U-373 cells. Results showed that except for nuclear localization, there were no specific cytoplasmic organelles that PKC-alpha or -beta translocated to following HuIFN alpha-2b treatment. Electron micrographs of PKC-beta in proliferating cells depicted 1.34-fold more PKC-beta in the nucleus than in the cytoplasm and a 1-min HuIFN alpha-2b (500 units/ml) treatment transiently increased PKC-beta immunoreactivity in the cytoplasm (1.95-fold) and nucleus (1.97-fold). In …