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Full-Text Articles in Life Sciences

Changes In Tissue-Specific Fatty Acid Composition Of The Freshwater Alewife (Alosa Pseudoharengus) In Response To Temperature, William D. Schregel Dec 2013

Changes In Tissue-Specific Fatty Acid Composition Of The Freshwater Alewife (Alosa Pseudoharengus) In Response To Temperature, William D. Schregel

Biology Theses

Ectotherms are known to alter the composition of the cell membrane in response to changes in environmental temperature. Tissue-specific fatty acid composition in the alewife (Alosa pseudoharengus) was examined in response to both warm and cold temperature challenges administered over an approximate one month period. Gill, muscle, and liver tissues were analyzed prior to the start of the temperature challenge (initial), following the temperature challenges (survivors), and on those fish that did not survive the temperature challenges (mortalities). Significant differences were found between fatty acid composition of initial fish and survivors for membrane-incorporated fatty acids (polar) and for stored fatty ...


The Incidence Of Antibiotic Resistance In Mesophilic Aeromonas Isolated From The Buffalo River And From A Non-Urban Site Upstream, Amy L. Chapman Dec 2013

The Incidence Of Antibiotic Resistance In Mesophilic Aeromonas Isolated From The Buffalo River And From A Non-Urban Site Upstream, Amy L. Chapman

Biology Theses

Antibiotics are commonly used in agriculture and industry and their discharge is commonly seen in rivers, like the Buffalo River. This antibiotic discharge may cause a selective environment which favors the growth of antibiotic resistant Aeromonas. To study the effect of urban pollution on the antibiotic resistance in Aeromonas, 229 Aeromonas isolates were collected from fish tissues as well as sediment and water samples collected from the Buffalo River and a non-urban site (Cazenovia Creek). Seven different Aeromonas taxa were identified using biochemical tests. There were 124 (54%) isolates that were classified as atypical, which was the most commonly seen ...


Homing Behavior In Response To Displacement And Orientation Of The Northern Diamondback Terrapin (Malaclemys Terrapin Terrapin) In Barnegat Bay, New Jersey, Nicole M. Lainhart Dec 2013

Homing Behavior In Response To Displacement And Orientation Of The Northern Diamondback Terrapin (Malaclemys Terrapin Terrapin) In Barnegat Bay, New Jersey, Nicole M. Lainhart

Biology Theses

Increasing urbanization of the Barnegat Bayestuary in New Jersey has subjected northern diamondback terrapins to substantial habitat loss. Understanding whether terrapins have homing behavior, and determining the types of orientation cues they use to aid in this behavior, is important for conservation management. To test their homing behavior, nine non-gravid female terrapins were outfitted with biotelemetry tracking devices and data loggers and were displaced 4 km north and/or south. Eight of nine terrapins successfully returned home; the one terrapin that did not return home was inadvertently captured in a crab pot. Urbanization and shoreline development of the north displacement ...


Recruitment And Survival Of Post-Parasitic Juvenile Mussels In An East Texas River, David S. Bakkin Aug 2013

Recruitment And Survival Of Post-Parasitic Juvenile Mussels In An East Texas River, David S. Bakkin

Biology Theses

Freshwater mussels (order Unionoida) are the most imperiled group of fauna in North America. The factors driving this decline chiefly affect juvenile recruitment and survival, rather than adult mortality. However, our present knowledge generally consists of inferences from studies of adult distributions. Juvenile mussels are rarely collected in the field, leaving our understanding of this critical period in the mussel life cycle incomplete. Popular hypotheses, most notably that shear stress during floods scours small mussels from the substrate and largely confines mussel beds to sheltered areas, are supported by circumstantial evidence and have rarely been tested directly. The role of ...


The Effects Of Calcium Concentration And Food Levels On Daphnia, Fawn Goodberry Aug 2013

The Effects Of Calcium Concentration And Food Levels On Daphnia, Fawn Goodberry

Biology Theses

Many physiological processes of Daphnia are negatively affected at low calcium concentrations. The concentration of calcium within lake water influences how Daphnia populations will survive and reproduce in natural environments. An experiment was designed to test the effects of calcium concentration and food level on the growth and reproduction of a Daphnia hybrid. Daphnia pulex x Daphnia pulicaria were reared in a soft water medium at three calcium concentrations (2.5mg/L, 1.0mg/L, 0.50mg/L) and high and low food levels (5.6 x 105 and 5.6 x 104 cells of the algae Ankistrodesmus ...


Utilizing Maxent To Improve And Explain A Species Distribution Model For Freshwater Mussel Species In East Texas, Kirian Bregan Heffentrager Jun 2013

Utilizing Maxent To Improve And Explain A Species Distribution Model For Freshwater Mussel Species In East Texas, Kirian Bregan Heffentrager

Biology Theses

One of the greatest challenges in landscape ecology has been determining the degree to which landscape level environmental characteristics effect the distribution of freshwater mussels. Freshwater mussels have long been regarded as valuable indicators of lotic system health because they are often the first organisms to exhibit a response to changes in their environment. Understanding distributional patterns of mussels is consequently a valuable conservation and management tool. Here, I evaluated the improvement of predictive modeling software by applying MAXENT to the distributions of two freshwater mussel species, the Texas Pigtoe (Fusconia askewi), a state threatened species, and the Rock Pocketbook ...


Bactericera Cockerelli: Range Expansion, Candidatus Liberibacter Solanacaerum Detection, And Microbial Community Analysis, Alex Arp May 2013

Bactericera Cockerelli: Range Expansion, Candidatus Liberibacter Solanacaerum Detection, And Microbial Community Analysis, Alex Arp

Biology Theses

The potato psyllid (Bactericera cockerelli) is an emerging pest of solanacious crops. Traditionally their range expanded from Guatemala north through the central United States and into southern California. Recent expansions have led to potato psyllids residing as far south as Nicaragua and as for north as Washington State. Potato psyllids were also accidentally imported into New Zealand. These expansions are alarming because potato psyllids transmit Candidatus Liberibacter solanacaerum (Lso), the bacteria associated with Zebra Chip disease in potato, which results in millions of dollars in damages annually. In this study, potato psyllid and Zebra Chip range expansion into Central America ...


Propagation Of Homalodisca Coagulata Virus-01 Via Homalodisca Vitripennis Cell Culture, Anna Biesbrock May 2013

Propagation Of Homalodisca Coagulata Virus-01 Via Homalodisca Vitripennis Cell Culture, Anna Biesbrock

Biology Theses

The glassy-winged sharpshooter (Homalodisca vitripennis) is a highly vagile and polyphagous insect, which feeds on more than 100 plant species throughout the southwestern United States. Sharpshooters are the predominant vector of Xylella fastidiosa (Xf), a xylem-limited bacterium that is the causal agent of Pierce's disease (PD) of grapevine. Infected H. vitripennis transmit the bacterium while feeding. The rise of PD has been economically damaging for agriculture and H. vitripennis have become a target for disease control. A dicistrovirus identified as Homalodisca coagulata virus-01 (HoCV-01) has been associated with an increase in mortality rates within infected H. vitripennis populations. A ...


Cellular Mechanisms Of Pathogenesis Of Pseudomonas Aeruginosa, Omar Jorge Castillo May 2013

Cellular Mechanisms Of Pathogenesis Of Pseudomonas Aeruginosa, Omar Jorge Castillo

Biology Theses

Epithelial permeability is distorted by Pseudomonas aeruginosa elastase (PE) and changes in barrier function are caused by disruption of tight junction (TJ) proteins occludin, zonula occludens (ZO)-1 and alterations of the cytoskeleton. Increase in paracellular permeability is caused, in part, by activation of cellular signaling transduction pathways. The exact signaling mechanisms that lead to epithelial disruption are not yet fully understood. I sought to evaluate whether PE exposure can activate the epidermal growth factor receptor (EGFR) and whether, PE-induced TJ disruption was dependent upon activation of the extracellular signal-regulated kinases (ERK) arm of the mitogen-activated protein kinase (MAPK) pathway ...


Physiological Consequences Of Compensatory Growth: A Look At Snake Species Exhibiting Differential Sexual Size Dimorphism, Kaitlyn Pettingill May 2013

Physiological Consequences Of Compensatory Growth: A Look At Snake Species Exhibiting Differential Sexual Size Dimorphism, Kaitlyn Pettingill

Biology Theses

Although many life-history traits are inflexible, extrinsic factors are likely responsible for variation in attributes such as growth rates and ultimately adult body size. Nutritional stress during natal periods, in particular, has significant long-term consequences for adult characteristics. It is thought that poor natal nutrition leads to either the diversion of subsequent energy intake into compensatory growth or delayed maturation. Diversion of energy, to achieve compensation, however does not come without consequence; immune defense is a resource-demanding activity, which can trade- off with traits such as growth. Relatively little is known about the intra- or interspecific variation in immunological capabilities ...


Ground-Truthing Maxent In East Texas Rivers, David F. Ford May 2013

Ground-Truthing Maxent In East Texas Rivers, David F. Ford

Biology Theses

Unionid mussels are a guild of freshwater, sedentary filter-feeders, which play a critical role in freshwater systems. Mussels are currently experiencing a global decline in both species richness and abundance, due to invasive species, human alteration of water systems, and climate change. In North America, which is considered to have the highest global diversity of bivalve species, native mussels are currently declining rapidly with at least 37 species considered to already be extinct. If extant mussel species are to be preserved, then it is vital that conservation efforts be prioritized towards areas in which they are likely to be found ...