Exotic invasive aquatic weeds such as alligator weed (Alternanthera philoxeroides) threaten native ecosystems by interfering with native plant communities, disrupting hydrology, and diminishing water quality. Development of new tools to combat invaders is important for the well being of these sensitive areas. Integrated pest management offers managers an approach that combines multiple control methods for better control than any one method used exclusively. In a greenhouse and field study, we tested the effects of selective herbicide application frequency, native competitor plant introduction, and their integration on alligator weed. In the greenhouse study, alligator weed shoot, root, and total biomass were reduced with one herbicide application, and further reduced with two. Alligator weed cumulative stem length and shoot/root ratio was only reduced after two applications. In the greenhouse, introduction of competitors did not affect alligator weed biomass, but did affect shoot/root ratio. The interaction of competitor introduction and herbicide did not significantly influence alligator weed growth in the greenhouse study. In the field, alligator weed cover was reduced after one herbicide application, but not significantly more after a second. Introduction of competitor species had no effect on alligator weed cover, nor did the interaction of competitor species and herbicide application. This …

N-Acylethanolamines (NAEs) are fatty acid derivatives in plants that negatively influence seedling growth. N-Lauroylethanolamine (NAE 12:0), one type of NAE, inhibits root length, increases radial swelling of root tips and reduces root hair numbers in a dose dependent manner in Arabidopis thaliana L. (ecotype Columbia). A forward genetics approach was employed by screening a population of T-DNA “activation-tagged” developed by the Salk Institute lines for NAE resistance to identify potential genes involved in NAE signaling events in Arabidopsis thaliana L. (ecotype Columbia). Seeds of the activation tagged lines were grown at 0, 25, 30, 50, 75 and 100 µM N-lauroylethanolamime (NAE 12:0). Ten plants which displayed NAE tolerance (NRA) seedling phenotypes, compared with wildtype (Columbia, Col-0) seedlings were identified. I focused on one mutant line, identified as NRA 25, where the tolerance to NAE 12:0 appears to be mediated by a single dominant, nuclear gene. Thermal asymmetric interlaced (TAIL) PCR identified the location of the T-DNA insert as 3.86 kbp upstream of the locus At1g68510. Quantitative PCR indicated that the transcript level corresponding to At1g68510 is upregulated approximately 20 fold in the mutant relative to wildtype. To determine whether the NAE tolerance in NRA 25 is associated with overexpression of …

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most abundant environmental pharmaceutical contaminants. In this study, a proteomic analysis was conducted to identify proteins differentially expressed in gill tissue of zebrafish (Danio rerio) after a 14-day exposure to the NSAIDs ibuprofen or naproxen. A total of 104 proteins with altered expression as indicated by 2-dimensional electrophoresis were analyzed by liquid chromatography with ion trap mass spectrometry (MS/MS). A total of 14 proteins fulfilled our requirements for identification which included consistency among replicate gels as well as successful MS/MS ion searches with the MASCOT database. The most prominent feature of the differential protein expression observed after NSAID exposure was an up-regulation of proteins belonging to the globin family which are involved in the transport of oxygen from gills and availability of heme molecules required for synthesis of cyclooxygenase. Differential expression was observed at exposure concentrations as low as 1-10 µg/L indicating that altered gene expression may occur in fish subjected to environmentally realistic levels of NSAID exposure.

This study looked at effects of organic solvents dimethylsulfoxide, dimethylformamide and acetone at 0.01%, 0.05% and 0.1% concentration on germination and seedling development wetland plants. Even at 0.01% level, all solvents affected some aspect of seed germination or seedling growth. Acetone at 0.01% was least toxic. Root morphological characteristics were most sensitive compared to shoot morphological characteristics. This study also looked at bioconcentration patterns of antimicrobial compounds triclosan, triclocarban and methyl-triclosan in wetland plants exposed to Denton Municipal Waste Water Treatment Plant effluent. Bioconcentration patterns of antimicrobial compounds varied among species within groups as well as within organs of species. The highest triclocarban, triclosan and methyltriclosan concentration were in shoot of N. guadalupensis, root of N. lutea and in shoots of P. nodous respectively.

West Nile virus (WNV) is a geographically endemic mosquito-borne flavivirus that has spread across the United States infecting birds, mosquitos, humans, horses and other mammals. The wide spread nature of this virus is due to the ability of the mosquito vector to persist in broad, ecological diverse environments across the United States. In this study, mosquito populations in North Texas region were sampled for detection of Wolbachia, blood meal source, and WNV. The ultimate goal of this study was to examine the potential of a biocontrol agent, Wolbachia sp. that colonizes the hindgut of various insects, including mosquitos, as a natural means to interrupt virus transmission from mosquitos to other hosts, including humans. In Australia, Wolbachia sp. from fruit flies (Drosophila melanogaster) have been successfully used to block transmission of a similar pathogenic virus from mosquitos responsible for transmission of Dengue fever. Here, mosquitoes were collected using CDC style Gravid Traps in Denton, Texas, from October 2012 through September 2014. Collected mosquitoes were identified, sexed, and categorized as to the amount of host blood in their alimentary system using a Zeiss Axio Zoom microscope (Carl Zeiss Microscopy, LLC, Thornwood, NY). Culex quinquefaciatus was the dominant blood engorged species collected. Smaller …

Super-resolution 3D imaging was achieved using newly synthesized photoactivatable quantum dot (PAQ dot) probes. Quantum dots were modified with a novel quencher system to make them photoactivatable. The unique properties of these PAQ dots enable single-fluorophore localization in three dimensions using a confocal microscopy optical sectioning method. Myosin and tropomyosin of rabbit myofibrilar bundles were specifically labeled with the newly synthesized PAQ dot. A sufficient number of single quantum dots were photoactivated, localized and reduced to their centroid and then reconstructed to a super-resolution image. The acquired super-resolution image shows a lateral and an axial sub-diffraction resolution and demonstrates ultrafine striations with widths less than 70 nm that are not evident by conventional confocal microscopy. The striations appear to be related to nebulin thin filament binding protein. This newly developed imaging system is cutting edge for its high resolution and localization as well its simplicity and convenience.

The Texas Stream Team (TST) is one of an increasing number of citizen science water monitoring programs throughout the US which have been continuously collecting surface water quality data under quality assurance protocols for decades. Volunteer monitoring efforts have generated monitoring datasets that are long-term, continuous, and cover a large geographic area - characteristics shown to be valuable for scientists and professional agencies. However, citizen science data has been of limited use to researchers due to concerns about the accuracy of data collected by volunteers, and the decades of water quality monitoring data collected by TST volunteers is not widely used, if at all. A growing body of studies have attempted to address accuracy concerns by comparing volunteer data to professional data, but this has rarely been done with large-scale, existing datasets like those collected by TST. This study assesses the accuracy of the volunteer water quality data collected across the state of Texas by the TST citizen science program between 1992-2017 by comparing it to professional data from corresponding stations during the same time period, as well as comparing existing and experimental data from a local TST partner agency. The results indicate that even large-scale, existing volunteer and professional …

Upland cotton (Gossypium hirsutum L.) is the world's most prominent fiber crop. Cotton transformation is labor intensive and time consuming, taking 12 to 18 months for rooted T0 plants. One rate limiting step is the necessary production of somatic embryos. In other recalcitrant species, ectopic expression of three genes were shown to promote somatic embryogenesis: WUSCHEL (WUS), SHOOT MERISTEMLESS (STM), and BABY BOOM (BBM). WUS is responsible for maintaining stem-cell fate in shoot and floral meristems. STM is needed to establish and maintain shoot meristems. STM and WUS have similar functions but work in different pathways; overexpression of both together converts somatic cells to meristematic and embryogenic fate. BBM encodes an AP2/ERF transcription factor that is expressed during embryogenesis and ectopic expression of BBM reprograms vegetative tissues to embryonic growth. In prior studies, these genes were constitutively expressed, and cultures did not progress beyond embryogenesis because the embryogenic signal was not turned off. In our study, we set out to use these genes to increase the efficiency of cotton transformation and decrease the time it takes to regenerate a plant. A disarmed cotton leaf crumple virus (dCLCrV) vector delivers WUS, STM, or BBM into cotton tissue cultures through Agrobacterium tumefaciens …

The purpose of this study was to analyze the current and pre-service conditions that can affect student teachers' preparedness to pass the science portion of the EC-6 Texas Examinations for Educator Standards (TExES), one of the mandatory certification exam to become a teacher in Texas. Two types of prediction models were employed in this study: binomial logistic regression and multiple linear regression. The independent variables used in this study were: final grade in BIOL 1082, classification of students, transfer status, taken college biology, taken college chemistry, taken college physics, taken college environmental science, taken college earth science, attending college part-time, number of credits taken during the semester, first-generation college student, relatives with degree in education, and current GPA. The dependent variable of this study was the posttest score on science portion of the EC-6 TExES practice exam. A total of 170 preservice teachers participated this study. This study used students enrolled in BIOL 1082, who volunteered to take a Biology for Educators QualtricsTM survey and the EC-6 TExES practice exam in a pretest (start of semester) and posttest (end of semester) form. The findings of this study revealed that the single best predictor of preservice teachers' performance on the science …

Stomata are specialized plant structures required for gaseous exchange with the outer environment. During stomata formation, the cytoskeleton plays an important role in controlling the division of the individual cells leading to the generation of the stomata complex. Two mutants that affect microfilament and microtubule organization in subsidiary mother cells include brk1 and dcd1. While only 20% of the subsidiary cells in the brk1 and dcd1 single mutants are abnormally shaped, it was reported that there is a synergistic effect between the brk1 and dcd1 mutations in the brk1; dcd1 double mutant since 100% of the subsidiary cells are abnormal. The focus of this research is to try to understand this synergistic effect by investigating the actin cytoskeleton and nuclear position in the single and double mutants. The reported results include the observation that the size of actin patch was largest in the wild-type subsidiary mother cells (SMCs) and smallest in dcd1 and brk1; dcd1 SMCs and that brk1 and brk1; dcd1 double mutants had fewer actin patches than wild-type and dcd1 SMCs. Additionally, we observed that some SMCs that did not have actin patches still underwent nuclear migration suggesting that nuclear migration may not be solely dependent on actin …

Multi-walled carbon nanotube aggregates can be suspended in the aqueous phase by natural organic matter. These aggregates are ingested by filter feeding zooplankton. Ingested aggregates result in decreased growth and decreased reproduction. These effects may be caused by reduction in energy input from normal feeding behavior. pH alters natural organic matter structure through changes in electrostatic repulsion. Altered natural organic matter structure changes multi-walled carbon nanotube aggregate size. This size variation with variation in pH is significant, but not large enough a change in size to alter toxicity, as the aggregate size range remains well within the particle size selection of the organisms.

Plant microtubules play essential roles in cell processes such as cell division, cell elongation, and organelle organization. Microtubules are arranged in highly dynamic and ordered arrays, but unlike animal cells, plant cells lack centrosomes. Therefore, microtubule nucleation and organization are governed by microtubule-associated proteins, including a microtubule-severing protein, katanin. Mutant analysis and in vitro characterization has shown that the highly conserved katanin is needed for the organization of the microtubule arrays in Arabidopsis and rice as well as in a variety of animal models. Katanin is a protein complex that is part of the AAA+ family of ATPases. Katanin is composed of two subunits, katanin-p60, a catalytic subunit and katanin-p80, a regulatory subunit. Spastin is another MT-severing protein that was identified on the basis of its homology to katanin. In animal cells, spastin is also needed for microtubule organization, but its functionality has not yet been investigated in plants. To initiate an exploration of the function of katanin-p60 and spastin in Zea mays, my research goal was to generate tools for the expression and purification of maize katanin-p60 and spastin proteins in vitro. Plasmids that express katanin-p60 and spastin with N-terminal GST tags were designed and constructed via In-Fusion® cloning …

It has been shown previously in our laboratory that zebrafish produce trypsin from their gills when they are under stress, and this trypsin is involved in thrombocyte activation via PAR2 during gill bleeding. In this study, I investigated another role of the trypsin that is secreted from zebrafish. This investigation has demonstrated a novel role of trypsin in zebrafish. Not only did this investigation demonstrate the role of trypsin in zebrafish behavior, but also it showed that PAR2 might be the receptor that is involved in trypsin-mediated behavioral response. In addition, we have shown that Gq and ERK inhibitors are able to block the trypsin pathway and prevent the escaping behavior. Finally, the results of this investigation suggest that the cells that respond to trypsin are surface cells, which have an appearance similar to that of neuromast cells.

Previous studies have shown that fish release alarming substances into the water to alert their kin to escape from danger. In our laboratory, we found that zebrafish produce trypsin and release it from their gills into the environment when they are under stress. By placing the zebrafish larvae in the middle of a small tank and then placing trypsin at one end of the tank, we observed that the larvae moved away from the trypsin zone and almost to the opposite end of the tank. This escape response was significant and did not occur in response to the control substances, bovine serum albumin (BSA), Russell's viper venom (RVV), and collagen. Also, previously, we had shown that the trypsin could act via a protease-activated receptor-2 (PAR2) on the surface of the cells. Therefore, we hypothesized that trypsin would induce a change in neuronal activity in the brain via PAR2-mediated signaling in cells on the surface of the fish body. To investigate whether the trypsin-responsive cells were surface cells, we generated a primary cell culture of zebrafish keratinocytes, confirmed these cells' identity by specific marker expression, and then incubated these cells with the calcium indicator Fluo-4 and exposed them to trypsin. By …

Development is a dynamic process characterized by critical periods in which organ systems are sensitive to changes in the surrounding environment. In the current study, critical windows of embryonic growth and kidney development were assessed in the embryonic chicken. All‐trans retinoic acid (tRA) influences not only organogenesis and cell proliferation, but also targets metanephric kidney nephrogenesis. Embryonic chickens were given a single injection of tRA on embryonic day 8. tRA decreased embryo, kidney, and heart mass from day 16 to day 18. However, mass specific kidney and heart masses showed no differences. Whole blood, plasma, and allantoic fluid osmolality were altered in tRA treated embryos from day 16 to day 18. In addition, hematocrit, red blood cell count, and hemoglobin concentration were altered in tRA treated embryos. The results suggest that although nephrogenesis was not affected by tRA, the developing osmoregulatory system was altered in tRA treated embryos.

Six initial phage isolates with high titer lysates were obtained using Streptomyces toxytricini B-5426 as the host bacterium. These isolates were named Goby, Toma, Yosif, Yara, Deema, and Hsoos. However, upon completion of the sequencing, it was found that the Yara and Hsoos isolates were identical, as were Goby and Deema. As a result, final analysis was completed on only the four unique isolates. All of the phages mentioned above were isolated from soil samples from different locations. Also, they had different sizes of plaques, ranging from 0.3 – 0.9mm. Yosif had the largest plaque size. Yara's head diameter was 79nm with tail diameter of 94nm.

Forensic STR analysis is limited by the quality and quantity of DNA. Significant damage or alteration to the molecular structure of DNA by depurination, crosslinking, base modification, and strand breakage can impact typing success. Two methods that could potentially improve STR typing of challenged samples were explored: an in vitro DNA repair assay (PreCR™ Repair Mix) and whole genome amplification. Results with the repair assay showed trends of improved performance of STR profiling of bleach-damaged DNA. However, the repair assay did not improve DNA profiles from environmentally-damaged bloodstains or bone, and in some cases resulted in lower RFU values for STR alleles. The extensive spectrum of DNA damage and myriad combinations of lesions that can be present in forensic samples appears to pose a challenge for the in vitro PreCR™ assay. The data suggest that the use of PreCR™ in casework should be considered with caution due to the assay’s varied results. As an alternative to repair, whole genome amplification (WGA) was pursued. The DOP-PCR method was selected for WGA because of initial primer design and greater efficacy for amplifying degraded samples. Several modifications of the original DOP-PCR primer were evaluated. These modifications allowed for an overall more robust amplification …

Current energy and environmental challenges are driving the use of cellulosic materials for biofuel production. A major obstacle in this pursuit is poor ethanol tolerance among cellulolytic Clostridium species. The first objective of this work was to establish a potential upper boundary of ethanol tolerance for the cellulosome itself. The hydrolytic function of crude cellulosome extracts from C. cellulolyticum on carboxymethyl cellulose (CMC) with 0, 5, 10, 15, 20 and 25% (v/v) ethanol was determined. Results indicated that the endoglucanase activity of the cellulosome incubated in 5% and 10% ethanol was significantly different from a control without ethanol addition. Furthermore a significant difference was observed in endoglucanase activity for cellulosome incubated in 5%, 10%, 15%, 20% and 25% ethanol in a standalone experiment. Endoglucanase activity continued to be observed for up to 25% ethanol, indicating that cellulosome function in ethanol will not be an impediment to future efforts towards engineering increasing production titers to levels at least as high as the current physiological limits of the most tolerant ethanologenic microbes. The second objective of this work was to study bioethanol production by a microbial co-culture involving Clostridium cellulolyticum and a recombinant Zymomonas mobilis engineered for the utilization of oligodextrans. The …

While obesity is now recognized as a major health concern in Ghana, the major drivers, causal factors, and their spatial variation remain unclear. Nutritional changes and lack of physical activity are frequently blamed but the underlying factors, particularly cultural values and practices, remain understudied. Using hot spot analysis and spatial autocorrelation, this research investigates the spatial patterns of obesity in Ghana and the explanatory factors. We also use focus group discussions to examine the primary cultural factors underlying these patterns. The results show that wealth, high education, and urban residence are the best positive predictors of obesity, while poverty, low education, and rural residence are the best (negative) predictors of obesity. Consequently, improving the socioeconomic status, for example, through higher levels of education and urbanization may increase obesity rates. Furthermore, the cultural preference for fat body as the ideal body size drives individual aspiration for weight gain which can lead to obesity. Thus, reducing obesity rates in Ghana is impossible without addressing the underlying cultural values.

Symbiotic nitrogen fixation occurs in plants harboring nitrogen-fixing bacteria within the plant tissue. The most widely studied association is between the legumes and rhizobia. In this relationship the plant (legumes) provides the bacteria (rhizobia) with reduced carbon derived from photosynthesis in exchange for reduced atmospheric nitrogen. This allows the plant to survive in soil, which is low in available of nitrogen. Rhizobia infect and enter plant root and reside in organs known as nodules. In the nodules the bacteria fix atmospheric nitrogen. The association between the legume, Medicago truncatula and the bacteria Sinorhizobium meliloti, has been studied in detail. Medicago mutants that have defects in nodulation help us understand the process of nitrogen fixation better. One such mutant is the Mtnip-1. Mtnip-1 plants respond to S. meliloti by producing abnormal nodules in which numerous aberrant infection threads are produced, with very rare rhizobial release into host plant cells. The mutant plant Mtnip-1 has an abnormal defense-like response in root nodules as well as defects in lateral root development. Three alleles of the Mtnip/latd mutants, Mtnip-1, Mtlatd and Mtnip-3 show different degrees of severity in their phenotype. Phylogenetic analysis showed that MtNIP/LATD encodes a protein belonging to the NRT1(PTR) family of …

Despite the variety of successful reports of the preservation, recovery, and identification of archaeological proteins in general, there are few positive reports regarding mass spectrometry-based identification of ceramic-bound proteins. In large part, this shortage is due to the lack of consideration for the unique taphonomic histories of such residues and, in general, methods development. Further, because negative results are rarely published, there is no baseline to which results can be compared. This paper attempts to address these challenges via a multi-pronged approach that uses mass spectrometry and complementary approaches to evaluate ceramic-bound protein preservation in both controlled, actualistic experiments, and in archaeological artifacts. By comparing the results obtained from protein-spiked, experimentally-aged ceramic to those obtained from both faunal and ceramic archaeological materials, an enhanced perspective on protein preservation and subsequent recovery and identification is revealed. This perspective, focusing on taphonomy, reveals why negative results may be the norm for ceramic artifacts when non-targeted methods are employed, and provides insight into how further method development may improve the likelihood of obtaining positive results.

The Deepwater Horizon oil drilling rig exploded on April 20, 2010, off the coast of Louisiana in the Gulf of Mexico. Following the spill, British Petroleum, leaser of the rig, set up a funding institution known as the Gulf of Mexico Research Initiative (GoMRI) to support research and understanding of the spill on the environments and peoples of the gulf. This outreach project was created alongside research of the RECOVER consortium, funded by GoMRI, to communicate what is happening within research labs around the country to understand the effect that the spill had on fish in pelagic and coastal regions of the gulf. The outreach project is composed of a short film (Deepwaters: The Science of a Spill, 18 min) and related outreach materials posted to Instagram (@FishandOilSpills).

Body size varies according to nutritional availability, which is of ecological and evolutionary relevance. The purpose of this study is to test the hypothesis that differences in adult body size are realized by increasing juvenile growth rate for white-tailed deer (Odocoileus virginianus). Harvest records are used to construct growth rate estimates by empirical nonlinear curve fitting. Results are compared to those of previous models that include additional parameters. The rate of growth increases during the study period. Models that estimate multiple parameters may not work with harvest data in which estimates of these parameters are prone to error, which renders estimates from complex models too variable to detect inter-annual changes in growth rate that this simpler model captures

Tissue samples from spotted gar (Lepisosteus oculatus) and largemouth bass (Micropterus salmoides) were collected from Caddo Lake. Gar and bass livers were subjected to histological investigation and color analysis. Liver color (as abs at 400 nm) was significantly correlated with total mercury in the liver (r2 = 0.57, p = 0.02) and muscle (r2 = 0.58, p = 0.01) of gar. Evidence of liver damage as lipofuscin and discoloration was found in both species but only correlated with liver mercury concentration in spotted gar. Inorganic mercury was the predominant form in gar livers. In order to determine the role of mercury speciation in fish liver damage, a laboratory feeding study was employed. Zebrafish (Danio rerio) were fed either a control (0.12 ± 0.002 µg Hg.g-1 dry wt), inorganic mercury (5.03 ± 0.309 µg Hg.g-1 dry wt), or methylmercury (4.11 ± 0.146 µg Hg.g-1 dry wt) diet. After 78 days of feeding, total mercury was highest in the carcass of zebrafish fed methylmercury (12.49 ± 0.369 µg Hg.g-1 dry wt), intermediate in those fed inorganic mercury (1.09 ± 0.117 µg Hg.g-1 dry wt), and lowest in fish fed the control diet (0.48 ± 0.038 µg Hg.g-1 dry wt). Total mercury was …