Life Sciences Commons^™

Conjugated Polymer Nanoparticles For Effective Sirna Delivery To Tobacco By-2 Protoplasts, Asitha T. Silva, Alien Nguyen, Changming Ye, Jeanmarie Verchot, Joong Ho Moon

Department of Chemistry and Biochemistry

Background

Post transcriptional gene silencing (PTGS) is a mechanism harnessed by plant biologists to knock down gene expression. siRNAs contribute to PTGS that are synthesized from mRNAs or viral RNAs and function to guide cellular endoribonucleases to target mRNAs for degradation. Plant biologists have employed electroporation to deliver artificial siRNAs to plant protoplasts to study gene expression mechanisms at the single cell level. One drawback of electroporation is the extensive loss of viable protoplasts that occurs as a result of the transfection technology.

Results

We employed fluorescent conjugated polymer nanoparticles (CPNs) to deliver siRNAs and knockdown a target gene in …

Conclusions About Niche Expansion In Introduced Impatiens Walleriana Populations Depend On Method Of Analysis, Lisa Mandle, Dan L. Warren, Matthias H. Hoffman, A. Townsend Peterson, Johanna Schmitt, Eric J. Von Wettberg

Department of Biological Sciences

Determining the degree to which climate niches are conserved across plant species’ native and introduced ranges is valuable to developing successful strategies to limit the introduction and spread of invasive plants, and also has important ecological and evolutionary implications. Here, we test whether climate niches differ between native and introduced populations of Impatiens walleriana, globally one of the most popular horticultural species. We use approaches based on both raw climate data associated with occurrence points and ecological niche models (ENMs) developed with Maxent. We include comparisons of climate niche breadth in both geographic and environmental spaces, taking into account differences …

A Comparison Of Job Responsibility And Activities Between Registered Dietitians With A Bachelor's Degree And Those With A Master's Degree, Stephanie M. Pillow

FIU Electronic Theses and Dissertations

Minimal educational requirements for Registered Dietitians (RDs) include a bachelor’s degree and practice program. Recently, a master’s degree was recommended. Studies have not established whether education affects employment. A secondary analysis of 2005 Dietetics Practice Audit data determined whether job responsibility, individuals supervised, and activities differed between 1,626 bachelor’s RDs (B-RDs) and 767 master’s (M-RDs) RDs, registered ≤5 years. Chi-square and ANOVA analyzed differences between B-RDs and M-RDs, at entry-level (0-3 years experience) and beyond-entry-level (3+-5 years experience). Beyond-entry-level B-RDs (31.8%) and entry-level M-RDs (31.9%) reported “supervisor/executive” responsibility more than entry-level B-RDs (26.5%; p=0.01). A higher percentage of M-RDs supervised …

Bilirubin: An Animal Pigment In The Zingiberales And Diverse Angiosperm Orders, Cary L. Pirone

FIU Electronic Theses and Dissertations

Strelitziaceae is a tropical monocot family comprising three genera and seven species: Ravenala Adans and Phenkospermum Endl., which are monotypic, and five species of Strelitzia Aiton. All species produce woody capsular fruits that contain vibrantly colored arillate seeds. Arils of the Strelitzia species are orange, those of Phenakospermum are red, and those of Ravenala are blue. Unlike most plant pigments, which degrade after cell death, aril pigments in the family persist for decades. Chemical properties of the compounds are unusual, and do not match those of known pigment classes (carotenoids, flavonoids, betalains, and the chlorophylls). I isolated the orange pigment …

Arctic Ecosystem Responses To Changes In Water Availability And Warming: Short And Long-Term Responses, Paulo C. Olivas

FIU Electronic Theses and Dissertations

Arctic soils store close to 14% of the global soil carbon. Most of arctic carbon is stored below ground in the permafrost. With climate warming the decomposition of the soil carbon could represent a significant positive feedback to global greenhouse warming. Recent evidence has shown that the temperature of the Arctic is already increasing, and this change is associated mostly with anthropogenic activities. Warmer soils will contribute to permafrost degradation and accelerate organic matter decay and thus increase the flux of carbon dioxide and methane into the atmosphere. Temperature and water availability are also important drivers of ecosystem performance, but …

Bilirubin Present In Diverse Angiosperms, Cary Pirone, Jodie V. Johnson, J. Martin E. Quirke, Horacio A. Priestap, David W. Lee

Department of Biological Sciences

Background and aims: Bilirubin is an orange-yellow tetrapyrrole produced from the breakdown of heme by mammals and some other vertebrates. Plants, algae, and cyanobacteria synthesize molecules similar to bilirubin, including the protein-bound bilins and phytochromobilin which harvest or sense light. Recently, we discovered bilirubin in the arils of Strelitzia nicolai, the White Bird of Paradise Tree, which was the first example of this molecule in a higher plant. Subsequently, we identified bilirubin in both the arils and flowers of Strelitzia reginae, the Bird of Paradise Flower. In the arils of both species, bilirubin is present as the primary pigment, and …

Assessment Of Submerged Vegetation As Indicators Of Irgarol Contamination, Melissa V. Fernandez

FIU Electronic Theses and Dissertations

Irgarol 1051 is a common antifoulant toxic to certain marine organisms. Submerged aquatic vegetation (SAV) are exposed to this herbicide when it leaches into the marine environment from painted structures, making SAVs ideal candidates to function as sentinel indicator of contamination. In the initial stage of this study, Coconut Grove and Key Largo Harbor were assessed for environmental exposure to Irgarol. Water, sediment and SAVs were collected, the latter two subject to automated solid phase extraction, and all samples analyzed by GC/MS-SIM for Irgarol and its metabolite, M1. Of the vegetation analyzed, Halodule and Syringodium had the highest capacity to …

Lower Aptian Ammonite Biostratigraphy In The Maestrat Basin (Eastern Iberian Chain, Eastern Spain). A Tethyan Transgressive Record Enhanced By Synrift Subsidence, J. A. Moreno-Bedmar, M. Company, T. Bover-Arnal, R. Salas, G. Delanoy, Florentin J. Maurrasse, A. Grauges, R. Martinez

Department of Earth and Environment

The present paper analyses the stratigraphic distribution of ammonites collected in the Lower Aptian sediments of the Maestrat Basin (E Spain). The faunal successions obtained from the systematic sampling of ten selected sections located in several sub basins led us to identify four biostratigraphic units (from base to top: Deshayesites oglanlensis, Deshayesites forbesi, Deshayesites deshayesi and Dufrenoyia furcata Zones) that are directly correlatable with the current Mediterranean standard zonation. This study further provides essential biochronologic information to accurately date the different lithostratigraphic units included in the interval studied. Thus, the upper part of the Xert Formation can be tentatively attributed …

Land Use And Climate Change Impacts On The Hydrology Of The Upper Mara River Basin, Kenya: Results Of A Modeling Study To Support Better Resource Management, Liya M. Mango, Assefa M. Melesse, Michael E. Mcclain, Daniel Gann, S. G. Setegen

GIS Center

Some of the most valued natural and cultural landscapes on Earth lie in river basins that are poorly gauged and have incomplete historical climate and runoff records. The Mara River Basin of East Africa is such a basin. It hosts the internationally renowned Mara-Serengeti landscape as well as a rich mixture of indigenous cultures. The Mara River is the sole source of surface water to the landscape during the dry season and periods of drought. During recent years, the flow of the Mara River has become increasingly erratic, especially in the upper reaches, and resource managers are hampered by a …

Sessile Snails, Dynamic Genomes: Gene Rearrangements Within The Mitochondrial Genome Of A Family Of Caenogastropod Molluscs, Timothy A. Rawlings, Martin J. Macinnis, Rudiger Bieler, Jeffrey L. Boore, Timothy M. Collins

Department of Biological Sciences

Background: Widespread sampling of vertebrates, which comprise the majority of published animal mitochondrial genomes, has led to the view that mitochondrial gene rearrangements are relatively rare, and that gene orders are typically stable across major taxonomic groups. In contrast, more limited sampling within the Phylum Mollusca has revealed an unusually high number of gene order arrangements. Here we provide evidence that the lability of the molluscan mitochondrial genome extends to the family level by describing extensive gene order changes that have occurred within the Vermetidae, a family of sessile marine gastropods that radiated from a basal caenogastropod stock during the …

Characterization Of Oscillatoria Spp. And Their Role In Black Band Disease Of Coral, Dina Stanic

FIU Electronic Theses and Dissertations

Black band disease (BBD) is a cyanobacterial dominated pathogenic consortium that affects corals worldwide. Recently two cyanobacteria (Oscillatoria strains 101-1 and 100-1) were isolated into culture from BBD. The aim of this study was to characterize the strains and assess their role in BBD pathogenesis. Light, scanning electron and transmission electron microscopy, coupled with 16S rRNA gene sequencing, were used for taxonomic characterization. Cyanotoxin production was assessed by enzyme-linked immunosorbent assay. Toxin identification was performed by high performance liquid chromatography. The ability of the strains to initiate BBD was tested on host coral fragments of Siderastrea siderea and Diploria strigosa …

Molecular Characterization Of Gcc8 Alpha, The Functional Homologue Of Human C8 Alpha In The Shark, Ginglymostoma Cirratum, Lydia Tatiana Aybar

FIU Electronic Theses and Dissertations

The focus of this study is to elucidate the components of the nurse shark (Ginglymostoma cirratum) membrane attack complex (MAC), specifically complement component C8a (GcC8u). Nurse shark C8a gene was cloned, sequenced, and analyzed and Western blot analysis performed to identify components of shark MAC. GcC8a consists of 2341 nucleotides that translate into a 589 amino acid sequence that shares 41.1% and 47.4 % identity with human and xenopus C8a, respectively. GcC8a conserves the MAC modular architecture and cysteine-rich backbone characteristic of complement proteins, including the cysteine residue that forms the C8a-y bond as well as the indel that is …

How Anthocyanin Mutants Respond To Stress: The Need To Distinguish Between Stress Tolerance And Maximal Vigour, Eric Jb Von Wettberg, Maureen L. Stanton, Justen B. Whittall

Department of Biological Sciences

Background: Anthocyanins are produced by plants in response to diverse stresses Mutants that block the anthocyanin biosynthetic pathway (A BP) at various steps can easily be compared across numerous abiotic stresses Hypothesis: Anthocyanins or their precursors are required for stress tolerance. Thus, ABP loss-of-function mutants should have proportionately lower fitness than wildtype plants under stress, compared with benign conditions In contrast, a decrease in maximal vigour the general capacity for growth and fecundity should be most pronounced under benign conditions that allow luxuriant growth by the most vigorous genotypes Tests: Determine whether, under stressful conditions. ABP loss-of-function mutants have relatively …

The Interactive Effects Of Predators, Resources, And Disturbance On Freshwater Snail Populations From The Everglades, Clifton B. Ruehl

FIU Electronic Theses and Dissertations

The origins of population dynamics depend on interplay between abiotic and biotic factors; the relative importance of each changing across space and time. Predation is a central feature of ecological communities that removes individuals (consumption) and alters prey traits (non-consumptive). Resource quality mitigates non-consumptive predator effects by stimulating growth and reproduction. Disturbance resets predator-prey interactions by removing both. I integrate experiments, time-series analysis, and performance trials to examine the relative importance of these on the population dynamics of a snail species by studying a variety of their traits. A review of ninety-three published articles revealed that snail abundance was much …

Effects Of Light And Nutrient Supply On Stable Isotope Composition And Fractionation In Nitrogen-Limited Seagrass Beds, Rebecca Jane Bernard

FIU Electronic Theses and Dissertations

This experiment investigated causes of seasonality of δ¹⁵N and δ¹³C values in Thalassia testudinum leaf tissue by manipulating plant demand and nutrient supply in situ for 13 months. I clearly demonstrated that seagrass elemental content, stable C and N isotopic content, morphology and the concentration of NH₄+ seagrass porewaters directly respond to manipulations of resources and also by the plant demand for nutrients to support growth. Isotopic values displayed marked seasonality with heavier values found in summer (δ¹⁵N=5.0% δ¹³C=-5.7%o) and lighter values in winter (δ¹⁵N=1.7%o δ¹³C= …

The Perceptions, Attitudes And Practices Of Registered Dietitians Regarding Functional Foods, Amanda Berhaupt

FIU Electronic Theses and Dissertations

The term “functional food” (FF) has a variety of definitions resulting in term ambiguity. It is unclear Registered Dietitians’ (RDs) understanding and practices about FF. A descriptive, cross-sectional study investigated RDs’ perceptions, attitudes and practices regarding FF. A national random sample (n=1800) of RDs was mailed a FF questionnaire, 385 (22%) responded. Given five definitions from food-nutrition authorities, the majority of RDs did not agree on a definition, although three-fourths (n=292, 75.8%) perceived fortified foods as FF. Registered Dietitians agreed FF could improve health (n=266, 69.1%), prevent disease (n=282, 73.2%) and treat clientele (n=246, 63.9%), however were neutral (41.6%) or …

Ants And Plants With Extrafloral Nectaries In Fire Successional Habitates On Andros (Bahamas), Suzanne Koptur, Pascale Williams, Zuriany Olive

Department of Biological Sciences

Honey baits were used to assess the activity and abundance of nectar-drinking ants in fire successional habitats of rocklands on Andros Island, Bahamas. Vegetation was sampled in pineyard and coppice habitats (the same communities as Florida’s pine rocklands and hammocks), revealing a larger proportion of taxa with extrafloral nectaries in coppice samples, but roughly equivalent cover of plants with extrafloral nectaries in pineyard and coppice vegetation. Ant activity was greater in pineyard than in coppice habitats, with time to discovery of baits the shortest in open and recently burned pineyards, and most of the baits experiencing recruitment of ants. Overgrown …

Impact Of Herbivore Identity On Algal Succession And Coral Growth On A Caribbean Reef, Deron E. Burkepile, Mark E. Hay

Department of Biological Sciences

Background: Herbivory is an important top-down force on coral reefs that regulates macroalgal abundance, mediates competitive interactions between macroalgae and corals, and provides resilience following disturbances such as hurricanes and coral bleaching. However, reductions in herbivore diversity and abundance via disease or over-fishing may harm corals directly and may indirectly increase coral susceptibility to other disturbances. Methodology and Principal Findings: In two experiments over two years, we enclosed equivalent densities and masses of either single-species or mixed-species of herbivorous fishes in replicate, 4 m2 cages at a depth of 17 m on a reef in the Florida Keys, USA to …

Specombined Estradiol And Lithium Increase Er-Α Mrna In Embryonic C57bl/6j Primary Hippocampal Cultures, James J. Valdés, Ophelia Weeks

Department of Biological Sciences

Estrogen replacement therapy (ERT) is commonly prescribed during menopause. Post-menopausal women also tend to suffer from bipolar disorders and as a result are prescribed mood stabilizers – in addition to ERT. There is a paucity of data on how combined hormones and mood stabilizers interact in regulating gene expression that led us to hypothesize that in primary cultures of mixed brain cells predominated by glia, combined 17β-estradiol (E2) and lithium chloride (LiCl) (E2/LiCl) will alter estrogen receptor-alpha (ER-α) mRNA expression. We quantified mRNA expression of ER-α using the cDNA of treated primary cultures of mixed brain cells from a previous …

Lithium Enhances Cortical Mrna Expression In Ovariectomized C57bl/6j Mice, James J. Valdés, Franchesca M. Ramirez, Barbara Juarez, Ophelia Weeks

Department of Biological Sciences

The hippocampus and cortex of the mammalian brain are regions involved in learning and long-term memory. Estrogen and lithium affect similar learning and memory molecular processes. We hypothesized that in ovariectomized mice lithium treatment will enhance genetic factors in the brain that are involved in neuroprotection, learning and memory. Our study used bilaterally ovariectomized (bOVX) C57BL÷6J mice treated for one month with 14.2 mM LiCl in their drinking water. Results indicate that LiCl-treated bOVX mice show enhanced cortical increases in mRNA expression of ER-alpha, NR1, Bcl-2, BDNF, and CaMkII-alpha; hippocampal mRNA showed no changes. Our results indicate that in bOVX …

Seasonal Differences In The Co2 Exchange Of A Short-Hydroperiod Florida Everglades Marsh, Jessica L. Schedlbauer, Steven F. Oberbauer, Gregory Starr, Kristine L. Jimenez

FCE LTER Journal Articles

Although wetlands are among the world's most productive ecosystems, little is known of long-term CO₂ exchange in tropical and subtropical wetlands. The Everglades is a highly managed wetlands complex occupying >6000 km² in south Florida. This ecosystem is oligotrophic, but extremely high rates of productivity have been previously reported. To evaluate CO₂ exchange and its response to seasonality (dry vs. wet season) in the Everglades, an eddy covariance tower was established in a short-hydroperiod marl marsh. Rates of net ecosystem exchange and ecosystem respiration were small year-round and declined in the wet season relative to the dry …

Fire And Grazing In A Mesic Tallgrass Prairie: Impacts On Plant Species And Functional Traits, Marko J. Spasojevic, Rebecca J. Aicher, Gregory R. Koch, Emily S. Marquardt, Nicholas Mirotchnick, Tiffany G. Troxler, Scott Collins

FCE LTER Journal Articles

Fire is a globally distributed disturbance that impacts terrestrial ecosystems and has been proposed to be a global “herbivore.” Fire, like herbivory, is a top-down driver that converts organic materials into inorganic products, alters community structure, and acts as an evolutionary agent. Though grazing and fire may have some comparable effects in grasslands, they do not have similar impacts on species composition and community structure. However, the concept of fire as a global herbivore implies that fire and herbivory may have similar effects on plant functional traits. Using 22 years of data from a mesic, native tallgrass prairie with a …

The Engaged University: Providing A Platform For Research That Transforms Society, Ali Whitmer, Laura Ogden, John Lawton, Pat Sturner, Peter M. Groffman, Laura Schnieder, David Hart, Benjamin Halpern, William Schlesinger, Steve Raciti, Sonia Ortega, Lindsey Rustad, Steward Ta Pickett, Mary Killilea

FCE LTER Journal Articles

Despite a growing recognition that the solutions to current environmental problems will be developed through collaborations between scientists and stakeholders, substantial challenges stifle such cooperation and slow the transfer of knowledge. Challenges occur at several levels, including individual, disciplinary, and institutional. All of these have implications for scholars working at academic and research institutions. Fortunately, creative ideas and tested models exist that provide opportunities for conversation and serious consideration about how such institutions can facilitate the dialogue between scientists and society