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  • Undergraduate Poster Abstracts
  • Environmental Science/Studies

    THU-224 BIOAVAILABLE IRON FROM NORTHERN HEMISPHERE GLACIERS

    • Jessica Miles ;
    • Emily Stevenson ;
    • Sarah Aciego ;

    THU-224

    BIOAVAILABLE IRON FROM NORTHERN HEMISPHERE GLACIERS

    Jessica Miles, Emily Stevenson, Sarah Aciego.

    University of Michigan, Ann Arbor, MI.

    As glaciers continue to melt at a rapid pace due to global warming, so too will the amount of glacial meltwater produced. This melt contains sediments that include an unknown quantity of bioavailable iron that is subsequently dumped into the oceans. The bioavailable iron is easily digested by phytoplankton, promoting algal blooms. Phytoplankton that are drawn to the large sources of iron could help to buffer the effects of greenhouse-gas-induced global warming by drawing CO2 down from the atmosphere through photosynthesis. While this may prove to be a silver lining in the face of severe glacial melt, it is important to determine how much bioavailable iron is discharged and how this varies geographically. We conducted a series of experiments, extracting the bioavailable iron, %BA (percent bioavailable iron), in subglacially produced sediments derived from glaciers in Greenland, Canada, Alaska, and Svalbard. Samples from glaciers in Svalbard and Alaska contain the largest concentrations of Fe in sediments; however, sediments from Greenland tend to contain a greater proportion of iron that is bioavailable compared to Svalbard and Alaska. We find a large range of %BA from the lowest, 6.3 %BA (Canada) to 63.5 %BA (south Greenland). Our results enhance the previously restricted range of %BA measurements from glaciers and quantify the total concentrations of Fe available from sediments. These results demonstrate that geographically distinct glaciers provide a varied quantity of total bioavailable iron to downstream environments and may potentially enhance oceanic phytoplankton productivity, increasing CO2 drawdown.

    FRI-224 URANIUM ABATEMENT IN DRINKING WATER WITH NATURAL CLAYS

    • Emilio Rivera II ;
    • Tiffany Fowler ;
    • Antonio S. Lara ;

    FRI-224

    URANIUM ABATEMENT IN DRINKING WATER WITH NATURAL CLAYS

    Emilio Rivera II, Tiffany Fowler, Antonio S. Lara.

    New Mexico State University, Las Cruces, NM.

    Following the Second World War, the world’s race for uranium drove the U. S. to heavy mining in the Four Corners area, leaving long-forgotten uranium tailings in its wake. After half a century of rain, wind, and snow, that uranium has found its way into the water table causing an epidemic among many economically limited Navajo, most of whom have no option but to drink the heavily contaminated water. This consumption of uranium in ppb concentrations is causing what has become known as “Navajo neuropathy” in addition to many other health problems. While energy intensive water filtration methods such as reverse osmosis are effective, they simply are not practical in this application. Due to remote locations, an absence of infrastructure, and an utter lack of funds, an appropriate solution is necessary. We hypothesize that natural clays are just that solution. Inductively-coupled plasma-mass spectrometer (ICPMS) analysis shows a decrease in uranium concentration when 10.0 mL of contaminated water was exposed to 0.5 g of 3 standard clays and 2 local clays, demonstrating that natural clays can be used to abate heavy metals such as uranium from drinking water starting at 150 ppb, to below the EPA cutoff of 30 ppb. While some types of clay work better than others as a result of their varying cation exchange capacities (CEC), we propose that using our technique, any natural clay can be used to abate uranium.

    THU-213 QUANTIFYING FOOD SPECIES PRODUCED BY ANCIENT CLAM GARDEN TECHNOLOGIES OF THE SALISH SEA

    • Sonni Tadlock ;
    • Skye Augustine ;
    • Marco Hatch ;

    THU-213

    QUANTIFYING FOOD SPECIES PRODUCED BY ANCIENT CLAM GARDEN TECHNOLOGIES OF THE SALISH SEA

    Sonni Tadlock1, Skye Augustine2, Marco Hatch1.

    1Salish Sea Research Center, Northwest Indian College, Bellingham, WA 2Gulf Islands National Parks Reserve, Sidney, BC, CA.

    Worldwide, human activities are resulting in drastically altering habitats and changing climate that is negatively impacting the abundance of natural resources. For Indigenous communities, food systems and ecosystems are inextricably linked to both individual and community health. First Nations, since time immemorial, have shaped the environments around them to create and maintain energy-efficient traditional technologies, which provide livelihood to their communities. One technology that has increased the resilience of coastal communities is the use of clam gardens, which are defined as purposely constructed intertidal rock-walled terraces. These have been shown in previous studies to increase the habitat and productivity of bivalve species and may also increase the area of collection for other traditional foods. One aspect of clam gardens that has not yet been fully quantified is the traditional food availability in the rock wall structure. The purpose of this study is to quantify the edible species found within the rock wall structure compared to a non-walled beach. Edible species were quantified using low-tide comparative surveys on 10 meter by 2 meter transect lines on walled beaches and non-walled beaches. Results show a greater abundance of edible invertebrate species associated with clam gardens compared to a non-walled beach. Additionally, the sizes of individual species are larger at the rock wall than of the individual species observed at the non-walled beach. The quantification of traditional technologies’ productivity solidifies the right of Indigenous communities to be sovereign nations that are able to determine the environment they leave for future generations.

    FRI-215 SOCIAL NETWORK INFLUENCES ON COMORBIDITY OF PHYSICAL AND MENTAL HEALTH SYMPTOMS IN COMMUNITIES EXPOSED TO MAJOR NATURAL HAZARDS

    • Jennifer Villalobos ;
    • Eric Jones ;

    FRI-215

    SOCIAL NETWORK INFLUENCES ON COMORBIDITY OF PHYSICAL AND MENTAL HEALTH SYMPTOMS IN COMMUNITIES EXPOSED TO MAJOR NATURAL HAZARDS

    Jennifer Villalobos1, Eric Jones2,3.

    1University of Colorado Denver, Denver, CO, 2University of Texas Health Science Center at Houston, TX, 3School of Public Health, The University of Texas at El Paso, El Paso, TX.

    Although many studies have documented relationships between engagement in social networks and health status, the influence of social relationships on the comorbidity of physical health with mental health has not been researched. The influence of different types of social networks on the co-occurrence of physical health symptoms and post-traumatic stress in disaster settings is examined here. Secondary data were analyzed from prior face-to-face interviews and collected via paper survey. Networks were created by asking respondents to list names of people with whom they have interacted in the past 2 years or with whom they could have interacted if they had the choice. Sites exposed to major natural hazards included 5 sites in Ecuador (n = 263) and  research sites in Mexico (n = 201). Hence, 4 general social network types were identified that might increase or decrease comorbidity of physical and mental health: tight network, extending network, subgroup network, and  sparse network, with tight network being the most dense and sparse network being the least dense type of networks among community members. Results suggest that people who have been highly impacted and/or resettled are buffered against additional health conditions when they are part of tighter networks, but show greater co-occurrence of health conditions when they are part of tighter networks in less impacted settings. Understanding the influence of social networks on comorbidity of physical and mental health symptoms would help plan social aspects (i.e., building friendship networks) of interventions after a natural disaster.

    THU-222 SOWING OUR PEASANT SEEDS: TRADITIONAL AND MITIGATION SEED STRATEGIES IN SAN RAMON, NICARAGUA

    • Adriana Murguia ;
    • Stacy Philpott ;

    THU-222

    SOWING OUR PEASANT SEEDS: TRADITIONAL AND MITIGATION SEED STRATEGIES IN SAN RAMON, NICARAGUA

    Adriana Murguia, Stacy Philpott.

    University of California, Santa Cruz, Santa Cruz, CA.

    In Nicaragua, hybrid seeds have been introduced promising greater yields and food consumption. For small-subsistence farmers, seed saving is a more viable alternative than purchasing hybrid seeds; however, challenges remain in maintaining seed quality. Challenges to seed loss and strategies for seed saving have not been well documented. We look forward to investigating the efficacy of traditional and mitigation methods for seed saving by documenting the types of seeds and frequency of seed saving losses experienced in the community of San Ramon, Nicaragua. The Unión de Cooperativas Agropecuarias (UCA) San Ramon is a cooperative in Nicaragua that has been conducting food-security based projects to reduce food insecurity among coffee farmers. We will conduct a qualitative survey with 1 seed bank manager and 30 households that are project beneficiaries. The objective of the project is to continue capacity building of successful seed saving practices and strengthen food security initiatives for cooperative members.

    THU-223 LEAF LITTER INPUT RATES ALONG RIPARIAN FORESTS OF DIFFERENT SUCCESSIONAL AGES

    • Glen Beavers Allen ;
    • Frank Camacho ;

    THU-223

    LEAF LITTER INPUT RATES ALONG RIPARIAN FORESTS OF DIFFERENT SUCCESSIONAL AGES

    Glen Allen Beavers1, Frank Camacho2.

    1University of Hawaii at Hilo, Hilo, HI, 2University of Guam, Mangilao, GU.

    Leaf litter input is an important ecological process that forms the base of many terrestrial and aquatic food webs. While leaf litter input rates are well studied in temperate climates, they are poorly understood in tropical climates, especially in riparian areas. We analyzed differences in leaf litter input between streams in late successional and early successional riparian forests of the Las Cruces Biological Station in Costa Rica. Litter was collected with baskets placed along the banks of the streams approximately 4 m apart. Samples were collected every 2 to 3 days then taken to the lab to be dried, sorted, and weighed. We found no significant difference in total litter input between streams, but did find a significant difference between litter types with leaves as the dominant form of litter input. This suggests that leaf litter input is fairly uniform across riparian areas despite the contrast in environments. Because leaves contain vital nutrients such as carbon, nitrogen, and phosphorous upon which many detrital food webs depend, these results may lead to changes in the way riparian forest restoration efforts are managed in the future.

    FRI-213 CO2 FLUX IN FINE AND COARSE SOILS OF INTERMITTENT RIVERS AND EPHEMERAL STREAMS

    • Alana Dixon ;
    • Erika Gallo ;
    • Thomas Meixner ;

    FRI-213

    CO2 FLUX IN FINE AND COARSE SOILS OF INTERMITTENT RIVERS AND EPHEMERAL STREAMS

    Alana Dixon, Erika Gallo, Thomas Meixner.

    The University of Arizona, Tucson, AZ.

    While arid and semi-arid regions cover 1/3 of the Earth’s land surface, the soil biogeochemistry of intermittent rivers and ephemeral streams (IRES) is not as well understood as that of their perennial counterparts. This project identifies trends in CO2 respiration of soils in 2 urban and 2 rural ephemeral streams located in southern Arizona. Fine soils are thought to have higher soil respiration rates according to the inverse-inverse texture hypothesis. Measurements were taken of soil moisture, pH, electrical conductivity, and particle size using a laser PSA, and soil organic matter content via loss on ignition. Soil sample incubations were conducted for rainfall levels of 5mm (average) and 25mm (above average). CO2 concentration ([CO2]) was measured using an infrared gas analyzer before and after a wetting. CO2 was measured twice each day during the first 3 days following wetting, then once every 2 days. Preliminary results show the 46% fine-particle soil had the highest average [CO2] for the first 3 measurements in both trials. The 30% fine-particle soil had a higher [CO2] than the 15% fine-particle soil which had a higher [CO2] than the 38% fine-particle soil. Measurements from the 46% fine-particle soil supported the hypothesis that fine and neutral soils will have higher average and peak CO2 flux rates than coarse and acidic soils. However, measurements from more coarse soils did not conform to the hypothesized trend. These results may be used to improve understandings of nutrient cycling and soil biogeochemistry in IRES.

    THU-226 VIABLE ANTIBIOTIC-RESISTANT BACTERIA ARE DISSEMINATED ON AIRBORNE PARTICULATE MATTER FROM CATTLE FEED YARDS

    • Loren Hensley ;
    • Kimberly Wooten ;
    • Phil Smith ;
    • Gregory D. Mayer ;

    THU-226

    VIABLE ANTIBIOTIC-RESISTANT BACTERIA ARE DISSEMINATED ON AIRBORNE PARTICULATE MATTER FROM CATTLE FEED YARDS

    Loren Hensley, Kimberly Wooten, Phil Smith, Gregory D. Mayer.

    Texas Tech University, Lubbock, TX.

    Increasing incidence of antibiotic resistance is cause for concern because, without effective antibiotics, humans could quickly lose the war on bacterial disease. Antibiotic-resistant bacteria are generated in settings where antibiotics are used in large quantities, such as hospitals, veterinary clinics, and animal production facilities. Some estimates suggest that the amount of antibiotics used in animal production industries constitutes as much as 80% of total North American antibiotic usage. Recently, our group described aerial dissemination of antibiotics, bacteria, and antibiotic-resistant genes on airborne particulate matter emanating from cattle feedlots. Because the previous study used a sequencing approach, results were unable to confirm viability of the fugitive bacteria. Given the robust population diversity observed in the previous study, we hypothesized that particulate matter could harbor viable bacteria, and that members of this population would exhibit antibiotic resistance. Here we show that numerous bacteria associated with feedlot particulate matter are indeed viable in laboratory culture, including several isolates that are antibiotic resistant. Particulate matter samples isolated on sterile filters placed downwind of feed yards were cultured in Luria broth and tripticase soy broth, both with and without tetracycline at 50 µg/ml. Viable bacteria included a subset of those observed by sequencing. Tetracycline-resistant isolates were observed on tripticase soy agar plates using the disc diffusion method. Isolates were identified by sequencing of the 16S rRNA gene variable regions 1-3. This study validates previous sequencing-based investigations and provides proof of principle that viable antibiotic-resistant bacteria are emitted from feedlots via airborne particulate matter.

    FRI-223 CRAB ABUNDANCE AND PREDATION RISK WITHIN LEAF LITTER DENSITIES IN THE STREAM

    • Jerry Route ;
    • Justin Montemarano ;

    FRI-223

    CRAB ABUNDANCE AND PREDATION RISK WITHIN LEAF LITTER DENSITIES IN THE STREAM

    Jerry Route1, Justin Montemarano2.

    1College of Micronesia, Pohnpei, FM, 2Armstrong State University, Savannah, GA.

    The abundance and risk of predation for freshwater crabs (Pseudothelphusidae: Allacanthospittieri) were studied in stream habitats with different leaf litter densities at the Las Cruces Biological Station near San Vito in Coto Brus County, Costa Rica. Crab abundance was positively correlated with leaf litter density, and carapace length was negatively correlated with stream order. No difference was detected in predation risk between streams with low or high leaf little density. There was no significant correlation found between the crab abundance and the average total length of fish or fish abundance. Similarly, there was no significant correlation between the size of fish and the size of crabs. Fish, birds, and water rats of the genus Nectomysare are potential crab predators, but we did not find evidence that leaf litter density affected predation rates, suggesting that litter as refuge wasn’t important. The method used to capture crabs (i.e., baited minnow traps) produced a sex bias, and other methods may be employed to reduce this bias. Overall, pseudothelphusid crabs were found to be active, important components of the streams of Las Cruces Biological Station, but the factors limiting predation rates are not well understood.

    THU-215 MARINE SECONDARY ORGANIC AEROSOL FORMATION

    • Ramon Gonzalez Perez Sr. ;
    • Xiaofei Wang ;

    THU-215

    MARINE SECONDARY ORGANIC AEROSOL FORMATION

    Ramon Gonzalez Perez Sr.1, Xiaofei Wang2.

    1Universidad de Guanajuato, Guanajuato, MX, 2University of California, San Diego, La Jolla, CA.

    Secondary organic aerosols (SOA) account for a major fraction of aerosols in the atmosphere. They play a crucial role in affecting climate. However, a detailed knowledge of their formation, properties, and transformation in the atmosphere is still unclear. Few studies have reported how SOA are formed over the ocean area. Therefore, this study investigates characteristics and formation pathways of marine SOA in a controlled laboratory environment that closely simulates real oceanic conditions. Biogenic volatile organic compounds (BVOC) are produced from phytoplankton and bacteria from a marine aerosol reference tank (MART) that is filled with seawater. Marine SOA are formed due to the oxidation of BVOC by mixing the hydroxyl radical (OH), the most important atmospheric oxidant, with BVOC in a smog chamber. Then, the marine SOA are analyzed by aerosol mass spectrometry (AMS) and scanning mobility particle sizer (SMPS) in order to study the individual particle composition and size, respectively. The biological variation in the MART tank is tracked. The effects of biology in seawater on SOA formation is studied.

    THU-227 THE EFFECTS OF STREAM DRYING ON AQUATIC INVERTEBRATES IN THE CHALONE CREEK WATERSHED

    • Miranda Gonzales ;
    • Michael Bogan ;
    • Stephanie M. Carlson ;

    THU-227

    THE EFFECTS OF STREAM DRYING ON AQUATIC INVERTEBRATES IN THE CHALONE CREEK WATERSHED

    Miranda Gonzales, Michael Bogan, Stephanie M. Carlson.

    University of California, Berkeley, Berkeley, CA.

    Drought intensity has increased in recent years, creating a need for studies on the effects these events have on ecosystems. With increased drought, streams are at risk of altered flow patterns, including complete stream drying and longer periods without flow. Our objective is to understand how drought and stream drying impact biodiversity in the Chalone Creek watershed, an intermittent stream network in northern California. Intermittent streams naturally dry for part of the year, but vary from having short (weeks) to extended (months) dry periods. We collected aquatic invertebrates from 10 reaches in the watershed to measure invertebrate density and species richness at each site. Flow sensors at each site measured how long each site had been flowing prior to sampling and the overall annual flow duration. In the lab, invertebrates were counted and classified as to species, and we compared density and species richness with flow duration. Annual flow duration for all sites ranged from 10% to 60%, and flow prior to sampling ranged from 15 to 106 days. We found 116 invertebrate species across all sites, with individual site richness ranging from 12 to 54 species. Higher annual flow resulted in higher species richness and lower density of invertebrates. Sites that had been flowing longer before sampling also exhibited higher species richness compared to sites that had flowed for less time. If extreme drought continues, intermittent streams will dry for longer periods, reducing biodiversity. Additionally, streams that currently flow year-round may become intermittent and lose biodiversity.

    THU-225 ASSESSING THE IMPACTS OF CLAM GARDENS ON INVERTEBRATE SPECIES DIVERSITY IN THE SALISH SEA

    • Amy Irons ;
    • Skye Augustine ;
    • Marco Hatch ;

    THU-225

    ASSESSING THE IMPACTS OF CLAM GARDENS ON INVERTEBRATE SPECIES DIVERSITY IN THE SALISH SEA

    Amy Irons1, Skye Augustine2, Marco Hatch1.

    1Salish Sea Research Center, Northwest Indian College, Bellingham, WA, 2Gulf Islands National Park Reserve and Northwest Indian College, Bellingham, WA.

    The world’s oceans are impacted by human interactions that create largely negative consequences. However, Indigenous societies developed technologies and management practices that positively benefit ecosystems and have sustained resources for millennia. One such technology is clam gardens. Clam gardens are intertidal rock-wall structures constructed by First Nations people that trap sediment and extend the area for productive clam growth. Clam gardens have been shown to increase abundance and growth rate of clams when compared to non-walled beaches. In fact, ethnographic studies have shown that clam gardens had multiple purposes besides being productive clam habitats. To better understand the ecological role of clam gardens, the purpose of this study was to quantify increased biodiversity associated with clam garden rock walls. Specifically, the following hypothesis would be tested: a clam garden rock wall will have greater species diversity when compared to a non-walled beach. Invertebrate species diversity was determined by using randomly placed 50 x 50 cm quadrats and identifying all species to the lowest taxonomic level. Preliminary results show that invertebrate biodiversity is higher on a clam garden wall when compared to a non-walled beach. This research shows the ecological impact of clam gardens on intertidal invertebrate species’ richness and acts as an example of how traditional technologies can aid in maintaining complex marine invertebrate communities. In this way, we can look to First Nations technologies that have worked for millennia and see how these technologies may be implemented in modern applications to create sustainable solutions that can positively impact resilient ecosystems.

    FRI-226 USING SSR FINGERPRINTING TO EVALUATE GENETIC DIVERSITY OF XYLELLA FASTIDIOSA IN TEXAS

    • Sara Valliani ;
    • Lisa Morano ;
    • Saima Valliani ;

    FRI-226

    USING SSR FINGERPRINTING TO EVALUATE GENETIC DIVERSITY OF XYLELLA FASTIDIOSA IN TEXAS

    Sara Valliani, Lisa Morano, Saima Valliani.

    University of Houston-Downtown, Houston, TX.

    Plant diseases caused by Xylella fastidiosa, a Gram-negative bacillus, have emerged as a significant threat to the American viticulture. Xylella fastidiosa grows in the xylem of plants and causes Pierce’s disease (PD) in grapevines. A concern of the wine industry is to understand how PD is spreading from vineyard to vineyard and from one region of the state to another. To apprehend the epidemiology of PD spread, we have analyzed 8 distinct small sequence repeats (SSR) from X. fastidiosa cultures extracted from vineyards in different counties. SSRs change more rapidly than other areas of the genome and help us determine how bacteria spread on short time scales (months, years). Our main goal is to compare 8 different X. fastidiosa isolates from Texas counties and create a cluster analysis to better understand how isolates move between counties. DNA will be extracted from cultures and a cluster diagram of genetic variability built. Rather than estimating the size of SSRs with gels, we are using the melt temperatures from the QRT PCR reactions for each SSR. We plan to use this method with all 8 isolates to address our epidemiological questions.

    FRI-227 TRANSITION AREA BETWEEN PRIMARY AND SECONDARY FORESTS AND ITS EFFECTS ON PREDATION RATES

    • Ashley Carlisle ;
    • Andrea Romero ;

    FRI-227

    TRANSITION AREA BETWEEN PRIMARY AND SECONDARY FORESTS AND ITS EFFECTS ON PREDATION RATES

    Ashley Carlisle1, Andrea Romero2.

    1Colorado State University, Fort Collins, CO, 2University of Wisconsin-Whitewater, Whitewater, WI.

    Understanding the similarities and differences between primary and secondary forests is important because secondary forests are becoming a prominent feature in the landscape, yet we know little about their conservation value and their potential for replacing primary forests. The aim of this study is to better understand if predation rates along a shared edge of primary and secondary forests differ, and if distance from edge affects predation rate. We predict that, as distance increases from forest transition zone between primary and secondary forests, predation rates will increase. Using model caterpillars and 2 types of eggs, predation rates were assessed by placing models or eggs on a 100-meter transect stretching into both primary and secondary forests. Results concluded that egg type, forest type, and a combination of egg type and forest type are not significant in affecting predation rate. However, distance from the transition edge of primary and secondary forests was significant in predation rates. Exploring predation rates at the transition edge of primary and secondary forests, we may be able to predict and better understand secondary forest conservation value in comparison to primary forests in order to develop beneficial management solutions.

    FRI-214 RESURRECTION OF DIAPAUSING EMBRYOS IN TEMPORARY CHIHUAHUAN DESERT AQUATIC COMMUNITIES

    • Sergio Samaniegos ;
    • Elizabeth Walsh ;

    FRI-214

    RESURRECTION OF DIAPAUSING EMBRYOS IN TEMPORARY CHIHUAHUAN DESERT AQUATIC COMMUNITIES

    Sergio Samaniegos, Elizabeth Walsh.

    The University of Texas at El Paso, El Paso, TX.

    The Chihuahuan Desert receives approximately 20 cms of rain per year. Numerous species living in temporary habitats persist during droughts as resting stages that serve as colonists following subsequent rainfall events. When favorable conditions resume, a fraction of the diapausing embryos hatch. The others remain in a diapaused state creating an “egg bank”. Here we investigated how the length of desiccation impacts community structure and species persistence. We compared species composition of active communities with those formed after extended periods of desiccation (up to 17 yrs) in 10 temporary desert ponds to determine how length of dormancy affects hatching success in temporary desert aquatic habitats. Active populations were examined using a 64-micron plankton net. Sediments collected during dry phases were rehydrated, and emerging taxa were identified. Rotifers were identified to species, while other taxa were identified to family. Results showed that a subset of species found in active ponds hatched from desiccated sediments but unique taxa were also found. For example, rehydrated sediments from 1998 yielded 8 rotifer species, one fairy shrimp, a gastrotrich, and an assortment of protists. The active community of the temporary pond being investigated consists of 19 rotifers, several cladocerans, and a suite of other invertebrates. These results are comparable to those found in a similar study in Australia where 19% of rotifer species were recovered from sediments. Our results will help better predict how climate change-induced shifts in precipitation may impact patterns of zooplankton community structure in desert aridland aquatic ecosystems.

    FRI-222 NEW SENSORY STUDY OF SPECIES WITH NUCLEAR SIGNIFICANCE

    • Fernando Rodarte ;
    • Jessica Zapata ;
    • Mian Jiang ;

    FRI-222

    NEW SENSORY STUDY OF SPECIES WITH NUCLEAR SIGNIFICANCE

    Fernando Rodarte, Jessica Zapata, Mian Jiang.

    University of Houston-Downtown, Houston, TX.

    Residues of nuclear significance are involved in nuclear power plants, waste disposal, nuclear medicine, and other auxiliary sectors. They can be conventional as well as radioactive. In this work, we used iodide as a model species for their sensor application and potential, given the facts that iodide-131 is an active diagnostic agent and iodide itself is an essential nutritional component in the human diet. Spectrophotometry and electrochemical voltammetry were used for these characterizations. We found excellent spectrophotometric and voltammetric behavior owing to iodide in a very broad pH range. A carbon-based electrode can directly serve as the sensing substrate for iodide, with glassy carbon responding the best. Furthermore, our findings suggest that a conventional pencil lead can be used to detect iodide, which bears the potential for practical application for nuclear or nuclear-mimic sensory study. Our UV-Vis spectrophotometric study showed that iodide can react with other co-existing species to offer an optic sensing venue. The preliminary study revealed the complicated responding mechanism. In the end, we were able to develop new assays for iodide and iodide-like species, which opens a door for future nuclear medicine and nuclear sensing. [This work was supported by NRC-MSIP, NOAA B-WET, NASA-TSGC-NIP, and Welch Grant (BJ-0027).]

    THU-214 EFFECTS OF DROUGHT CONDITIONS ON THE PHOTOSYNTHETIC PERFORMANCE OF POPLARS (POPULUS SP.)

    • Elizabeth Parra ;
    • Greg Barron-Gafford ;
    • Rebecca Minor ;
    • Erik McFarland ;

    THU-214

    EFFECTS OF DROUGHT CONDITIONS ON THE PHOTOSYNTHETIC PERFORMANCE OF POPLARS (POPULUS SP.)

    Elizabeth Parra1, Greg Barron-Gafford2, Rebecca Minor2, Erik McFarland3.

    1The University of Texas at El Paso, El Paso, TX, 2The University of Arizona, Tucson, AZ, 3Tolt Middle School, Carnation, WA.

    Poplars are an important agro-forestry product used for both biofuel and paper production. Importantly, all poplars are not created equal; some poplars have the potential to produce isoprene, a compound thought to aid plants under temperature and water stress conditions. Our project observed how drought conditions modulated photosynthetic rates in 2 lineages of Populus trees, those that produce isoprene and those that have had the isoprene gene knocked out. We measured leaf-level photosynthesis and temperatures from the 2 lineages under high- and low-water exposure in a common garden experiment. We found that both lines had similar photosynthetic rates over the range of temperatures and water exposure levels measured. However, afternoon measurements were, at times, inconsistent with plants of the same treatment measured in the morning. Soil moisture and leaf water potential of the poplars showed the differential in irrigation had not actually yielded differences in the treatment conditions among the trees. Photosynthetic rates were then measured in the morning and afternoon to determine if the time of day influenced photosynthetic performance, even though conditions were controlled at the leaf level. Morning measurements showed that poplars reached higher rates of photosynthesis, but ultimately decreased faster than observed in the afternoon measurements. Ultimately, our experiment showed that isoprene did not aid in photosynthesis under heat stressed conditions, and that the common garden setting was not able to currently induce a water stress condition in the plants. Further research is needed to determine if drought conditions can be implemented in the common garden.

    FRI-225 SERUM-BORNE VASCULAR TOXICITY FOLLOWING INHALATION OF COMPLEX POLLUTANT MIXTURES

    • Lauren Heine ;
    • Guy Herbert ;
    • Bethany Sanchez ;
    • Katie Zychowski ;
    • Jacob McDonald ;
    • Jeremy Brower ;
    • June Liu ;
    • Matthew Campen ;

    FRI-225

    SERUM-BORNE VASCULAR TOXICITY FOLLOWING INHALATION OF COMPLEX POLLUTANT MIXTURES

    Lauren Heine1, Guy Herbert1, Bethany Sanchez1, Katie Zychowski1, Jacob McDonald2, Jeremy Brower2, June Liu2, Matthew Campen1.

    1The University of New Mexico, Albuquerque, NM, 2Lovelace Respiratory Research Institute, Albuquerque, NM.

    Inhalation of complex emissions induce inflammatory responses in the systemic vasculature which can lead to chronic diseases such as atherosclerosis. We examined the role of complex circulatory biomolecular changes following inhalation of combustion-source mixtures in terms of causing endothelial cell (EC) inflammatory responses and altering wound healing. We tested this through exposures to different variations of mixed vehicle emissions (MVE) generated in the laboratory by a mixture of fresh diesel and gasoline exhausts. Male C57BL/6 mice were exposed to 1 of 6 atmospheres (50 d, 6 h/d). The 6 atmospheres were filtered air (control group), MVE100 (100 μg/m3), MVE300 (300 μg/m3), MVE particulate matter (PM) without gas phase components, MVE PM without SVOCs, and also hardwood smoke (HWS). Serum obtained from mice after exposures was used to treat primary murine ECs at 5% vol/vol in media for 4 h to examine inflammatory gene expression. Serum was also tested on ECs for an electric cell-substrate impedance assay (ECIS) to assess its effect on endothelial barrier integrity and on cellular regrowth. We found elevated VCAM-1 gene expression for all of the atmospheres compared to the control group. Small impairments in regrowth after a wounding protocol were noted in cells incubated with serum from the MVE100 group. Interestingly, ECs incubated with serum from HWS mice showed a substantial impairment in regrowth compared to the control group. These findings confirm that bioactive changes occur in the serum following inhalation exposures to complex mixtures.