Biology Commons^™

The Biological Flora Of Coastal Dunes And Wetlands: Avicennia Germinans (L.) L., Robert I. Lonard, Frank W. Judd, Kenneth R. Summy, Hudson R. Deyoe, Richard Stalter

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Avicennia germinans (L.) L. is a pantropical, subtropical, and occasionally warm-temperate mangrove species that occurs on shorelines that have a broad horizontal tidal range. Also known as black mangrove, stands typically develop under anoxic, water-logged conditions in substrates of silt or clay. Black mangrove can tolerate salinity values ranging from 0 to 90 parts per thousand. Salt is excreted from salt glands on both leaf epidermal surfaces, and aerosol salt spray and salt crystals are frequently observed on the upper leaf epidermis. Avicennia germinans is viviparous. The embryos have no dormancy requirements, and there is no seed bank. This mangrove …

Fish Oil With Higher Dha Content And Voluntary Exercise Decreases Postmenopausal Bone Loss, Jameela Banu, Gabriel Fernandes

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

There is increasing evidence suggesting that fish oil (FO) decreases bone resorption by reducing osteoclastogenesis and regular exercise (EX) increases bone mass. EX is associated with increasing bone formation. Therefore, the combined effects of FO intake and EX may have additive effects by both increasing bone formation and decreasing bone resorption. To demonstrate this, we studied the effects of FO and EX on the bone of mice after an ovariectomyinduced bone loss.

Twelve months old C57BL/6 female mice were either sham operated or ovariectomized, divided into different dietary and EX group and maintained for 3 months before sacrifice.

The distal …

Efectos Del Cambio Climático En La Interacción Planta-Hormiga: Una Mini Revisión Sobre La Tolerancia Térmica, Florencio Luna Castellanos, Mariana Cuautle, Teresa Patricia Feria-Arroyo, Citlalli Castillo Guevara

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Sin duda alguna el clima está cambiando debido al aumento de la concentración de gases de efecto invernadero en la atmósfera provocado por la acción humana. Dichos cambios van a tener un efecto importante en algunas actividades humanas tales como la agricultura y también pueden afectar enormemente la distribución geográfica de los organismos vivos y por tanto sus interacciones. Las hormigas y las plantas tienen una larga historia evolutiva de interacción. La actividad de las hormigas y su relación con las plantas en los últimos años ha tenido un número creciente de estudios que están poniendo de relieve su papel …

The Breeding Bird Community Of A Remnant Urban Woodland In Mcallen, Texas, John S. Brush, Alexis Racelis, Timothy Brush

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

We conducted a breeding bird survey of a remnant thorn-forest at McAllen Nature Center in 2015 and 2016 to assess the breeding bird community and compare it to that of a larger, exurban refuge. We recorded 37 territorial species in McAllen Nature Center, including 15 species not reported at the exurban tract. Thirteen of these predominantly used the more open, human -maintained habitats in the northern and western sides of the park. The presence of many common thorn-forest birds, including a subset of the regions “South Texas specialty” species, is encouraging. Small remnant woodlands such as McAllen Nature Center may …

Carbon And Nitrogen Dynamics Of Anthropogenically Disturbed Seagrass Ecosystems, Alison Shepherd

Theses and Dissertations

As atmospheric CO2 concentrations continue to rise, understanding factors that influence size and longevity of carbon (C) pools within coastal and marine ecosystems (i.e., “blue carbon”) is critical. In 2013, the global average atmospheric CO2 concentration reached 396 ppm, which was the highest recorded level in the last 800,000 years. Recent research acknowledges the importance of “blue carbon” in the global C cycle, finding that these ecosystems capture up to 70% of organic C in the marine realm, rendering them one of the most efficient C sinks on the planet. Specifically, seagrass ecosystems are critically important to the global C …

Avian Communities In An Urbanizing Region: Abundance Patterns And Effects Of Local Habitat Features, John S. Brush

Theses and Dissertations

The Lower Rio Grande Valley of Texas has experience rapid population growth and increase of urban area since the mid-20th century. The goal of this thesis were to: 1) explore patterns of avian communities in suburban and remnant urban woodlands, with particular interest in native forest species, and 2) to assess how local habitat variables, such as number of native trees, affect avian communities in suburban habitats, and 3) provide recommendations to municipalities and homeowners to enhance urban habitats for birds. Results indicated that remnant urban woodlands provided habitat for common native forest bird species that otherwise avoided suburban habitats, …

Developing A Multimetric Index To Assess Resaca Ecosystem Health, Buford J. Lessley

Theses and Dissertations

As the only freshwater ecosystem in the lower Rio Grande Valley aside from the Rio itself, resacas are critical habitat for many species of flora and fauna. Old distributaries of the Rio Grande, resacas provided conveyance routes moving floodwater to the Laguna Madre. Today these wetlands are novel ecosystems and are artificially maintained. Urbanization and agriculture have lead to sedimentation, habitat loss, contaminants, poor water quality, and invasive species. The objective of this study was to assess and monitor resaca pools and to compose the Resaca Health Index (RHI) from selected indicators of ecosystem structure and function including leaf litter …

Conservación De Aves En México, Una Instantánea De 2015, Raúl Ortiz-Pulido, José L. Alcántara-Carbajal, Horacio De La Cueva, Juan Martínez-Gómez, Patricia Escalante Pliego, Sylvia M. De La Parra-Martínez, Teresa Patricia Feria-Arroyo, Steve Albert

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Más del 26% de las especies de aves que habitan en México está declinando. Los ornitólogos han propuesto diversas acciones para conservar algunas de ellas; sin embargo, se han hecho pocos esfuerzos por difundirlas. En este escrito, tomando en cuenta las nueve pláticas presentadas en un simposio científico realizado en 2015, resumimos la información sobre los esfuerzos de conservación de aves que se están llevando a cabo en el país. Dividimos los estudios en tres categorías: los que analizan cómo se hace la conservación en México, los que hacen conservación práctica y los que constituyen investigación ecológica básica tendiente a …

Sequencing Of The Complete Mitochondrial Genome Of Anastrepha Species, Francisco C. Rugama Ii

Theses and Dissertations

Several members of fruit flies in the vastly diverse Anastrepha (Schinner) genus (family Tephritidae), considered to be among the most important and devastating pests of vegetable and fruit crops, are distributed widely throughout the Americas. They attack several different kinds of fruit including citrus, which is of great economical importance in South Texas. The identification of these flies is based primarily on wing pattern and characteristics of the female genitalia, contrary to males, which cannot be distinguished at all. Misidentification of adults is a widespread problem, while identification at the larval stage is practically impossible. Currently, there are no published …

Effect Of Exotic Invasive Old World Climbing Fern (Lygodium Microphyllum) On Soil Properties, Pushpa G. Soti, Krish Jayachandran

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Old World climbing fern (Lygodium microphyllum) has become one of the most serious ecological threats to the integrity of the greater Everglades ecosystem of south Florida. In this study, we analyzed the effects of Old World climbing fern on surfacesoil characteristics at invaded sites in Florida. We compared soil characteristics of six invaded and adjacent uninvaded plots at three different locations. Our results show that the fern can grow and thrive in a wide range of soil types and the impact on the soil was site specific with effects being more prominent in sites with low nutrient status. Additionally, there …

Subspecific And Breeding Status Of The Common Yellowthroat (Geothlypis Trichas) At Santa Ana National Wildlife Refuge, Hidalgo County, Texas, Timothy Brush, Mark H. Conway

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

ABSTRACT—We confirmed the breeding of the Common Yellowthroat (Geothlypis trichas) during 2008–2015 at Santa Ana National Wildlife Refuge and presented measurement evidence that individuals belong to the Brownsville Common Yellowthroat, Geothlypis trichas insperata. This expands the known breeding distribution for this rare and local subspecies.

RESUMEN—Se confirm´o la reproducci´on de la mascarita com´un (Geothlypis trichas) durante 2008-2015 en Santa Ana National Wildlife Refuge y se presentaron pruebas de medici ´on que indican que los individuos pertenecen a la subespecie de mascarita com´un, Geothlypis trichas insperata. Esta informaci´on expande la distribuci´on de reproducci´on conocida de esta subespecie rara y local.

Calculating Evapotranspiration Of Arundo Donax Along The Rio Grande, Jose R. Escamilla Jr.

Theses and Dissertations

Invasive species have been recorded to cause large economic and ecological impacts on various ecosystems and their services. Locally, giant reed (Arundo donax L.), a woody grass native to the Mediterranean, adversely impacts riparian ecosystems in southwestern United States by aggressively displacing their native flora and fauna. Giant reed also has become a cause of concern for national water security, especially in water-limited areas of the arid southwestern United States. The main objective of this study is to provide the first, landscape-level estimates of water use by giant reed in the United States. Evapotranspiration was monitored using the eddy …

Linking Hydraulic Traits To Tropical Forest Function In A Size-Structured And Trait-Driven Model (Tfs V.1-Hydro), Bradley O. Christoffersen, Manuel Gloor, Sophie Fauset, Nikolaos M. Fyllas, David R. Galbraith, Timothy R. Baker, Bart Kruij, Lucy Rowland, Rosie A. Fisher, Oliver J. Binks

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Forest ecosystem models based on heuristic water stress functions poorly predict tropical forest response to drought partly because they do not capture the diversity of hydraulic traits (including variation in tree size) observed in tropical forests. We developed a continuous porous media approach to modeling plant hydraulics in which all parameters of the constitutive equations are biologically interpretable and measurable plant hydraulic traits (e.g., turgor loss point πtlp, bulk elastic modulus ε, hydraulic capacitance Cft, xylem hydraulic conductivity ks,max, water potential at 50 % loss of conductivity for both xylem (P50,x) and stomata ( …

One Health Interactions Of Chagas Disease Vectors, Canid Hosts, And Human Residents Along The Texas-Mexico Border, Melissa N. Garcia, Sarah O’Day, Susan P. Fisher-Hoch, Rodion Gorchakov, Ramiro Patino, Teresa Patricia Feria-Arroyo, Susan T. Laing, Joe E. Lopez, Alexandra Ingber, Kathryn M. Jones, Kristy O. Murray

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Background

Chagas disease (Trypanosoma cruzi infection) is the leading cause of non-ischemic dilated cardiomyopathy in Latin America. Texas, particularly the southern region, has compounding factors that could contribute to T. cruzi transmission; however, epidemiologic studies are lacking. The aim of this study was to ascertain the prevalence of T. cruzi in three different mammalian species (coyotes, stray domestic dogs, and humans) and vectors (Triatoma species) to understand the burden of Chagas disease among sylvatic, peridomestic, and domestic cycles.

Methodology/Principal Findings

To determine prevalence of infection, we tested sera from coyotes, stray domestic dogs housed in public …

Lack Of Interaction Between Erbb2 And Insulin Receptor Substrate Signaling In Breast Cancer, Sarah M. Farabaugh, Bonita T. Chan, Xiaojiang Cui, Robert Dearth, Adrian V. Lee

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Background: ErbB2 Receptor Tyrosine Kinase 2 (ErbB2, HER2/Neu) is amplified in breast cancer and associated with poor prognosis. Growing evidence suggests interplay between ErbB2 and insulin-like growth factor (IGF) signaling. For example, ErbB2 inhibitors can block IGF-induced signaling while, conversely, IGF1R inhibitors can inhibit ErbB2 action. ErbB receptors can bind and phosphorylate insulin receptor substrates (IRS) and this may be critical for ErbBmediated anti-estrogen resistance in breast cancer. Herein, we examined crosstalk between ErbB2 and IRSs using cancer cell lines and transgenic mouse models.

Methods: MMTV-ErbB2 and MMTV-IRS2 transgenic mice were crossed to create hemizygous MMTV-ErbB2/MMTVIRS2 bigenic mice. Signaling crosstalk …

Partitioning Controls On Amazon Forest Photosynthesis Between Environmental And Biotic Factors At Hourly To Interannual Timescales, Jin Wu, Kaiyu Guan, Matthew Hayek, Natalia Restrepo-Coupe, Kenia T. Wiedemann, Xiangtao Xu, Richard Wehr, Bradley O. Christoffersen, Guofang Miao, Rodrigo Da Silva

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Gross ecosystem productivity (GEP) in tropical forests varies both with the environment and with biotic changes in photosynthetic infrastructure, but our understanding of the relative effects of these factors across timescales is limited. Here, we used a statistical model to partition the variability of seven years of eddy covariance-derived GEP in a central Amazon evergreen forest into two main causes: variation in environmental drivers (solar radiation, diffuse light fraction, and vapor pressure deficit) that interact with model parameters that govern photosynthesis and biotic variation in canopy photosynthetic light-use efficiency associated with changes in the parameters themselves. Our fitted model was …

Characterizing Mesophotic Reef Fish Communities At Five South Texas Relic Coral-Algal Banks, Linda Marie Jordan

Theses and Dissertations

The South Texas Banks are a mesophotic coral ecosystem (30-150m deep). Understanding the community structure, biodiversity and, geographic connectivity of the South Texas Banks is essential with increasing threats from climate change, ocean acidification, invasive species, and pollution. In this study, a remotely operated vehicle (ROV) was used to examine the fish communities at five of the South Texas Banks: Big Adam, Hospital, Mysterious, North Hospital, and Southern. Reef fish were identified to the lowest possible taxon and enumerated from ROV transect video footage. A total of 3,838 demersal and pelagic fishes were recorded representing 61 species in 22 families …

South Padre Island Beach Management: Assessment Of Dune Restoration, Shelby Rose Bessette

Theses and Dissertations

Dune restoration is a common method of increasing coastal resilience. A dune restoration program was initiated by the City of South Padre Island, TX in 2010 consisting primarily of plantings of Sea Oats, Uniola paniculata, and Bitter Panicum, Panicum amarum and has continued approximately annually thereafter. These restoration efforts were evaluated in this study by comparing dune ecological structure and function among reference sites and restoration plots ranging in age from 2 to 5 years. Plant and animal communities were examined using a combination of quadrat sampling, funnel traps, pit-falls and sweep nets. Soil organic content and soil electric …

The Effect Of Manganese (Mn) On Cell Proliferation And Migration In The Michigan Cancer Foundation-7 (Mcf-7) Human Breast Cancer Cell Line In Vitro, Justin Lloyd Wendel

Theses and Dissertations

Manganese (Mn) is a common environmental element necessary for mammalian physiological processes. However, dietary excess or deficiency can lead to detrimental health effects. Therefore, I investigated the effect Mn has on breast cancer progression in vitro. Utilizing MCF-7 breast cancer cells an MTT assay was performed to identify proliferative potential. After 5 days, results showed 100 nM manganese chloride (MnCl2) had a significant (p<0.01) increase in cell number over control. Using a scratch wound-healing assay, 100 nM MnCl2 was found to increase cellular motility as well as induce a possible change in morphology and cytoskeletal organization. Given Mn was shown to localize in the mitochondrial, we investigated Mn-induced ROS expression. 500 nM Mn significantly decreased (p<0.05) ROS levels. Collectively, I provide evidence that Mn may potentially drive less aggressive cancer cells towards a more invasive phenotype.

Manganese-Reducing Bacterial Communities From A Hypersaline Estuary In South Texas Under Conditions Of Changing Salinity, Omar R. Elizondo, Rebecca Vasquez Villarreal, Sonia Y. Del Rio, Kristine L. Lowe

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Manganese reducing bacteria were quantified and enriched from sediments at two sites (ABC and LMT050) in the Laguna Madre of South Texas. Bacteria were tested for Mn(IV) reduction under different salinities. Denaturing gradient gel electrophoresis (DGGE) was used to profile bacterial communities from Mn(IV) saline enrichments. Results showed that the density of manganese reducing bacteria at ABC was 30X greater than LMT050. The ABC bacteria were able to reduce Mn(IV) at similar rates at different salinities; however, at LMT050, Mn(IV) reduction rates decreased at higher salinities. Three population genotypes were observed by DGGE. All were present and similarly abundant in …

Nesting Ecology Of The Northern Beardless-Tyrannulet (Camptostoma Imberbe) In The Lower Rio Grande Valley Of Texas, Usa, Scott M. Werner, Sallie J. Hejl, Timothy Brush

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

During 2002–2003, we studied the breeding ecology of the Northern Beardless-Tyrannulet (Camptostoma imberbe), a poorly known and rare permanent resident in the Lower Rio Grande Valley of Texas, United States of America. We found 28 nests in clusters of Spanish moss (Tillandsia usneoides) or ball moss (T. recurvata), 93% of which were in cedar elm (Ulmus crassifolia) trees. Nest-building, incubation, and nestling periods averaged 7.0, 14.0, and 18.5 days, respectively. Of the 28 nests, 43% were successful, while 38% of the failed nests showed obvious signs of depredation. Nests were located in …

A National Strategy For The Conservation Of Native Freshwater Mollusks, Megan Bradley, Robert S. Butler, Heidi L. Dunn, Catherine Gatenby, Patricia A. Morrison, Teresa J. Newton, Matthew Patterson, Kathryn E. Perez

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

In 1998, a strategy document outlining the most pressing issues facing the conservation of freshwater mussels was published (NNMCC 1998). Beginning in 2011, the Freshwater Mollusk Conservation Society began updating that strategy, including broadening the scope to include freshwater snails. Although both strategy documents contained 10 issues that were deemed priorities for mollusk conservation, the identity of these issues has changed. For example, some issues (e.g., controlling dreissenid mussels, technology to propagate and reintroduce mussels, techniques to translocate adult mussels) were identified in the 1998 strategy, but are less prominent in the revised strategy, due to changing priorities and progress …

Relationships Between Texas Tortoise Carapace Length, Home Range Size, And Habitat Selection At Sites With Invasive Grass, Kiley V. Briggs

Theses and Dissertations

Invasive grasses in south Texas have the potential to negatively impact the threatened Texas tortoise (Gopherus berlandieri) by reducing the availability of preferred foods (forbs) and may cause tortoises to travel farther, lead to reduced carapace length, and reduce the availability of refugia from heat stress. I used compositional analysis, regression, and ANOVA to explore relationships between invasive grasses and habitat use, home range size, and carapace length, as well as compared daily maximum temperatures between tussocks of an invasive and native grass. Forbs were ranked higher in use over invasive grasses in compositional analysis, but not strongly so (p …

Apoptotic And Necrotizing Mechanisms Of Recombinant Panton-Valentine Leukocidin In Thp1 Monocytes., Heriberto Deleon Iii

Theses and Dissertations

The Panton-Valentine Leukocidin (PVL) is a highly specialized bacterial exotoxin produced by Staphylococcus aureus. The increased degree of invasiveness of community associated methicillin resistant Staphylococcus aureus (CAMRSA) has been attributed to the relatively high rates of PVL produced by the pathogen, thus increasing pathogenicity and virulence. The increased rates of PVL encoding CAMRSA infections have been correlated with increased rates of necrotizing fasciitis, invasive osteomyelitis and invasive necrotizing pneumococcal infections. Previous research as revealed that PVL has the ability to induce apoptosis at low concentration (5nM-10nM) and necrosis (50-100nM) at high concentrations, with little detail on the mechanism of initiation. …

Jatropha Curcas Protoplast Isolation And Inhibitory Effects Of Culture, Christopher S. Lukaszewski

Theses and Dissertations

Improvement on the sub-tropical plant Jatropha curcas may increase the use of this drought tolerant oilseed crop for the production of biodiesel. One of the methods for enhancing a species is through genetic manipulation of the protoplast. Isolating protoplasts is challenging and culturing has many obstacles similar to those seen in tissue culture, such as oxidative browning. Successful isolation of J. curcas leaf protoplasts resulted in an average of 3.23 x 106 viable protoplasts/mL. However, protoplasts diminished within 2 days after culturing. A review of the potential solutions used for overcoming the inhibitory effects of culture may reveal further insight …

Characterizing Benthic Invertebrate Communities At Five South Texas Banks, Maria T. Cooksey

Theses and Dissertations

On the continental shelf off the coast of South Texas lie a series of hardbottom structures known as the South Texas Banks, which provide critical habitat for benthic organisms and pelagic fish species. The depth of the banks, a persistent nepheloid layer, and strong currents have hindered efforts to collect quantitative data on what inhabits the rocky outcrops and relic coral-algal reefs. Using a remotely operated vehicle, video data from five of the banks were collected in order to characterize the benthic communities. Southern and North Hospital Banks were found to be the most diverse of the studied South Texas …

Flowering And Seed Production In The Subtropical Seagrass, Halodule Wrightii (Shoal Grass), Joseph L. Kowalski, Hudson R. Deyoe

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Reproductive structures of the seagrass, Halodule wrightii Ascherson (shoal grass) are cryptic and ephemeral, but were found on several occasions at several sites over more than a decade in the subtropical Laguna Madre (USA). Structures align with descriptions for H. wrightii. Male, but no female flowers were found, but the numerous fruit-bearing shoots imply the occurrence of pistillate flowers. Mean seed bank density was 890 seeds m-2 (1900–5200 m-2). Sexual reproduction in H. wrightii is more common than previously believed and the seed bank reserve may contribute to its ecological role as a colonizer of disturbed sediments.

Genetic Structure Of Faucet Snail, Bithynia Tentaculata Populations In North America, Based On Microsatellite Markers, Kathryn E. Perez, Rebecca L. Werren, Christopher A. Lynum, Levi A. Hartman, Gabor Majoros, Rebecca A. Cole

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Bithynia tentaculata is believed to have been extirpated from North America during the last glacial maximum. It was reintroduced into North America via the Great Lakes basin in the 1800’s and has recently been expanding its geographic range. This snail serves as intermediate host for three trematodes that cause extensive recurring morbidity and mortality events in migratory water birds along the Mississippi River. Using twelve microsatellite loci for ~200 individual snails from 11populations in North America and Europe, we examined one of the three major geographic regions from which founding populations into the Great Lakes typically originate. Our data supports …

Translating Ecology, Physiology, Biochemistry And Population Genetics Research To Meet The Challenge Of Tick And Tick-Borne Diseases In North America, Maria Dolores Esteve-Gassent, Ivan Castro-Arellano, Teresa Patricia Feria-Arroyo, Ramiro Patino, Andrew Y. Li, Raul F. Medina, Adalberto A. Pérez De León, Roger Iván Rodríguez-Vivas

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several …

A Review On The Respiratory System Toxicity Of Carbon Nanoparticles, Maricica Pacurari, Kristine L. Lowe, Paul B. Tchounwou, Ramzi Kafoury

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The respiratory system represents the main gateway for nanoparticles’ entry into the human body. Although there is a myriad of engineered nanoparticles, carbon nanoparticles/nanotubes (CNPs/CNTs) have received much attention mainly due to their light weight, very high surface area, durability, and their diverse applications. Since their discovery and manufacture over two decades ago, much has been learned about nanoparticles’ interactions with diverse biological system models. In particular, the respiratory system has been of great interest because various natural and man-made fibrous particles are known to be responsible for chronic and debilitating lung diseases. In this review, we present up-to-date the …