TAMU-CC Campus Conference Proceedings
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Item Physical properties of dicarboxylated amino acid based surfactants in presence of diamine alkane counterions(2022-04) Fritz, Shayden; Billiot, Eugene; Billiot, Feri; Olson, MarkSurfactants are being examined for many different fields such as chemical, medical, cosmetics, and phar- maceutical applications. Surfactants consist of two regions a hydrophobic and a hydrophilic region. The hydrophobic region is the head in most surfactants, while the hydrophilic region is the tail. Surfactants are dynamic molecules and able to form micelles. The micelles form when the hydrophobic region aggregates together and forms different shapes. The concentration at which micelles are formed is called the critical micelle concentration (CMC). The CMC is the lowest concentration needed for the surfactants to form mi- celles. Many different types of surfactants can be created. The surfactants that were examined consisted of dicarboxylated amino acid groups (glutamic and aspartic) with a 11 and 13 caron chain hydrophobic tails. The CMC of these surfactants were measured in presence of 1,2 diamino ethyl, 1,3 diaminopropane, 1,4 diaminobutane, 1,5 diaminopentane and 1.6 diaminohexane. The effects of the different amino acids, tail structures, and counterions were tested by comparing the CMC values of the solution. The CMC was measured using the change in solution conductivity at different surfactant concentrations. Preliminary re- sults indicated that the hydrophobic chain length and the counterion type significantly effects aggregation behavior of the dicarboxylated amino acid surfactants in solution.Item A new method for compound-specific radiocarbon analysis of amino acids(2022-04) Baca, Jesus; Xu, Xiaomei; Lee, Wing Man (Charlotte); Zhang, LinRadiocarbon (14C) measurements have been used to provide reliable age estimates extensively in the fields of climatology, atmospheric science, biogeochemistry, and paleoceanography. However, most radiocarbon data is generated by measuring a bulk sample (e.g., bulk sediments), averaging 14C content of all carbon (C)-containing organic compounds (after inorganic C removal) rather than the specific organic compound produced by the organisms of interest during their life. Compound-specific radiocarbon analysis (CSRA) of amino acids (AA) can thus be a useful tool to precisely determine the age when the AAs were produced by the organisms. Robust methods for CSRA-AA are not yet widely available, partly due to the relatively small amount of C in AAs. Here we present a new approach of CSRA-AA combining semi-preparative ion- exchange chromatography (IC) and Accelerator Mass Spectrometry (AMS). Phenylalanine (Phe), glutamic acid (Glu), and methionine (Met) with their corresponding blanks were separated and collected using the IC as individual fractions from a commercial AA mixture, followed by graphitization and AMS analysis for 14C measurements. Current blank contribution was 5.2 and 16.6 g C with corresponding yields of 132 and 71.1 g C for Phe and Glu respectively. The obtained fraction modern (FM) with blank subtraction and error propagation was 0.9937±0.0065 for Phe and 1.1362±0.0271 for Glu, which is in line with the modern origins of the AA standards (Phe: 1.0276±0.0017; Glu: 1.0293±0.0005). Initial result for 14C-free Met standard was 0.0108±0.0062 (FM) with a blank contribution of 12.3 g C, consistent with its origin (0.0024±0.0005). The next step is to include additional AA standards and test real samples. Our ultimate goal is to conduct multiple-isotope measurements (13C, 14C, and 15N) of AAs preserved in sediments and separate the N cycling signals produced by surface plankton community from influences induced by diagenesis, microbial reworking, and horizontal transfer.Item Fingerprinting circulating tumor cell with characteristic membrane viscoelasticity by atomic force microscopy(2022-04) Lopez, Kimberly; Tamuno, Sophia; Brzezinski, Molly; Martin, Leisha; Xu, Wei; Sheng, JianAtomic Force Microscopy (AFM) is a powerful tool that can resolve nanoscale cell surface features (e.g. re- ceptors, channels) as well as perform the mechanical characterization of living cells and tissues. Anecdotal observations suggest that metastasized tumor cells bear their phenotypical “telltale” signatures in their mem- brane characteristics, i.e prostate cancer cells are often stiffer and more elastic than breast cancer. In this talk, we present a new methodology allowing us to quantify mechanical properties of cells through force- deformation relations (F-D curves) by nano-indentation, as well as develop a novel mathematical framework to quantify cell membranes’ viscoelasticity by performing Ting’s integral over F-D measurements to differen- tiate cancer phenotypes. We have developed a custom-made flow cell that enables simultaneous microscopic observation and AFM experimentation. Three cell lines, prostate cancer (PC3), breast carcinoma (T47D), and lung a-carcinoma (A549), are used for this kernel study. Cells are split once reaching a confluence of 70% and a 10% dilution of cells are plated on 12 mm diameter wafer. After 24-hour growth, the plated slides are transferred to in-house flow cell containing the corresponding culture medium. With an integrated LED illuminator sealed within a polydimethylsiloxane matrix underneath the wafer, simultaneous observation of live cells can be achieved by an integrated upright microscope. Indentation measurements are conducted with a “wet” AFM. Gold coated probes (k=0.03N/m) are used to allow measurement on soft cell membrane. Differing from past studies, we probe the membrane with large indentation. Standard Linear Solid model are fitted over measurements to obtain viscoelasticity parameters. Preliminary results show distinctive hys- teresis between loading and unloading of the membrane. It is also found that multi-power law model is more suitable for cancer characterization. Model parameters of three phenotypes show clear distinction and great potential to develop membrane viscoelasticity as a biomarker for cancer cell diagnostics and characterization.Item A coral’s true colors: Understanding color hues to assess coral health and welfare(2022-04) Herrera, Gabriella; Good, Alexandra M.; Hirota, Alexander; Razal, Catherine; Gaertner, Nicole; Sefcik, Justin; Gilbert, Jesse; Bahr, Keisha D.Coral reefs are one of the most biodiverse and productive ecosystems on Earth and various methods are utilized to monitor and assess coral health. But there is not a standardized method for quantifying coral health for corals held in captivity in zoos and aquariums. Therefore, a health assessment card using coral color to non-invasively monitor coral health was developed with the Texas State Aquarium (TSA). To quantify coral health, individual corals of each species were photographed in a controlled environment to develop color profiles. Simultaneously, nondestructive measurements of “health” were assessed using Pulse- Amplitude Modulation Fluorometry. These photosynthetic efficiency measurements determine how efficiently the symbiotic algae provides energy to the coral host. This project successfully corresponded photosynthetic efficiency to coral color to develop a Coral Health Assessment Card for all species at TSA. By implementing a standardized assessment of coral health, TSA can effectively and rapidly assess the health of their corals improving overall coral wellness. Consequently, the results of this work support TSA’s mission to support wildlife conservation by promoting education and conservation of coastal and marine ecosystems through their interactive exhibits.Item Corals in crisis: How temperature and nutrient fluctuations affect physiological responses of corals and their microbiome in Kāne’ohe Bay, Hawai’i(2022-04) Ruben, Zoe; Pinnell, Lee; Abdulla, Hussain; Turner, Jeffrey; Bahr, KeishaCoral reefs are the foundation to the social, cultural, and economic life in Hawai i; however, these reefs have not escaped the conditions that have ravaged coral reefs worldwide. Along the east coast of O ahu lies Kāne ohe Bay, which serves as a living laboratory with distinct difference in environmental gradients due to variation in circulation and residency times. Landward, there is a distinct gradient of cesspool presence and therefore a gradient of potential effluent intrusion and nutrient loading to these reefs. Together, these provide a unique opportunity to explore the impact of water quality and ongoing ocean warming on coral health, susceptibility and tolerance. This research investigates how temperature and nutrients influence the coral holobiont across a spatial and temporal environmental gradient. Pairs of known bleached/non-bleached corals were collected at two sites within Kāne ohe Bay which encompass this spatial gradient in temperature and nutrient influence. Corals were then subjected to experimental treatments (Control, Nutrient, Heated, Heated + Nutrient) for one month. Measurements of bleaching were collected at the beginning, middle, and end of the experiment and coral subsamples were collected at the beginning and end of the experiment for subsequent metagenomics analysis. I hypothesize that (A) coral subjected to a combined increase in temperature and nutrients will experience higher levels of bleaching and lower levels of survivorship, (B) historically non-bleached phenotypes will show higher levels of survivorship than their historically bleached counterparts, and (C) there will be an observed shift in microbial community composition across corals due to these stressors. If validated, these findings will support that coral bleaching susceptibility is manifested throughout the coral holobiont and the physiological response to stressors such as temperature and nutrient loading can be better understood and potentially mitigated, therefore supporting reef resiliency and restoration in the face of climate change.Item Large and fine-scale genetic structure of king snake eels (ophichthus rex) throughout the gulf of Mexico(2022-04) Chavez, Aline Trejo; O’Leary, Shannon; Cotton, Charles; Murwawski, Steve; Portnoy, David S.The king snake eel (Ophichthus rex), is a large, long-lived demersal predator and their distribution is limited to the Gulf of Mexico (GoM). King snake eels, like other ophichthids are data deficient, little is known about the O. rex biology. Eels were sampled throughout GoM (2011-17); eel tissues were prepared for sequencing using new molecular techniques resulting in robust ddRADseq SNP libraries. Genetic differentiation was estimated and new multidisciplinary approaches were used to explore large and fine-scale patterns of observed genetic connectivity. Previous studies of genetic connectivity in the Gulf of Mexico, have been limited to a few commercially important species and have been spatially limited to northern GoM (US). This study is unique, as it encompasses the entire species distribution and utilizes Gulf-wide fisheries-independent survey data (GoMRI 2011-2017). In this study we present evidence of large-scale population structure as reported in previous GoM connectivity studies and discuss potential drivers of fine-scale differentiation patterns within and among populations. Finally, this study explores potential implications for other fisheries- affected species and increases overall understanding of the underlying biology that drives observed patterns of genetic connectivity.Item Understanding the motivating factors and collegiate experiences of international non-stem students(2022-04) Salunke, Vedika S.; Bazner, Kevin J.The scale of movement of international students has increased dramatically since the 1950s, with the U.S. acting as a major destination owing to a good education system and generous funding of graduate studies (Alberts & Hazen, 2005). International students are not only a valuable financial asset to the host country, but they also enrich these host countries by their cultural and diverse backgrounds. International students also offer skilled, intellectual labor to the workforce with a wide range of knowledge across disciplines. According to Adhikari (2017), the number of international students in the United States is helping fill that demand but there is likely to be a push for more domestic students to enter the STEM field. There is also likely to be a shift in the reasons of students pursuing STEM fields because of the push to engage students in STEM fields earlier in their academic careers. This increase has led to more focus by researchers and institutions on STEM students, leaving out non-STEM students and their needs, experiences, and challenges. The purpose of this study is to understand the motivating factors and campus experiences of international students enrolled in non-STEM degree programs. Based on data collected from six participants in semi-structured interviews, the study explores: (1) Motivations of international students to enroll in a non-STEM program; (2) Their understanding of the OPT policies for STEM and non-STEM degree programs; (3) Academic challenges and college experiences of international non-STEM students. Limited support from recruiting agencies in the university’s application process, unawareness of STEM/ non-STEM differentiation and OPT policies, limited funding opportunities were the key findings of this study. Implications for this research will aid institutional leaders in better understanding the campus experiences of non-STEM international students and provide opportunities for improvements to student recruitment, campus programming, and academic support initiatives.Item A preliminary assessment and subsequent data evaluation of socioeconomic indicators of water quality(2022-04) Kramer, Mary; Yoskowitz, DavidUrban and agricultural runoff, changes to land use patterns and other anthropogenic sources of pollution affect water quality. Water quality is a key factor in ecosystem health. While physical and ecological models of pollution have been widely used to determine water quality, there is a significant gap in the use of socioeconomic metrics in these models. Numerous studies have explored the effects and/or trends of impaired water quality on socioeconomic factors. However, less information is available on the impact of socioeconomic factors on surface water quality. This study conducted a literature review of commonly assessed human activity and socioeconomic variables associated with water quality and assessed the availability of data to quantify these variables. The intent of this review is to apply available evidence-supported data to two case studies in the Texas Coastal Bend: Baffin Bay and San Antonio Bay. From the literature, commonly used socioeconomic metrics include land use/land change, community type, demographics, and population density. Possible point sources of pollution that relate to socioeconomic factors identified were wastewater treatment facilities, stormwater drainage, mining and oil extraction operations, and product manufacturing/ chemical production. Furthermore, this presentation will provide a preliminary assessment of data sources, data gaps, and recommendations.Item Tracking bottlenose dolphin movement and behavior in the Corpus Christi ship channel(2022-04) Mills, Eliza; Orbach, Dara N.Port Corpus Christi and Port Aransas, Texas, have undergone considerable infrastructure and oil exportation growth over the past 40 years. As humans continue to transform and exploit these coastal marine habitats, understanding dolphin and vessel interactions in the area is vital to improve conservation and management practices. As dolphins increased diving intervals and avoidance behavior in the presence of vessels, protecting marine mammals in areas of high vessel activity is urgent. To test the hypothesis that the movement patterns and behaviors of free-swimming bottlenose dolphins (Tursiops truncatus) are altered by vessel presence and size near Port Aransas, a shore-based digital theodolite is being used. Dolphin behavioral state and movement are analyzed in response to vessel activity. Distance between dolphin positions and habitat features are being calculated in ArcGIS Pro. Large vessels may elicit social and travel behavioral states as dolphins rode on the bows of most large tankers and cargo carriers. Dolphins mill and forage along channel banks and near the ferry crossing, suggesting that physical structures of concrete seawalls and mixing currents from vessel activity are utilized by dolphins to capture prey. In the morning and afternoon, dolphins oriented along the channel perimeter against the current flow with no positional changes in movement, indicating that tides may influence this population’s movement and behavior patterns. Understanding behavioral associations with diverse microhabitats in the Port Aransas area is crucial to conserve critical environments utilized by dolphins.Item Exploiting and securing programmable logic controllers(2022-04) Morales, Efrén López; Rubio-Medrano, CarlosMillions of people rely on vital utility infrastructure such as oil pipelines and water treatment plants. This makes them valuable targets for cyberattacks, and the security of the systems that manage this infrastructure, otherwise known as Industrial Control Systems (ICS), becomes ever more important. ICS are comprised of multiple control components, e.g., electrical, that work together to achieve an industrial goal, e.g., energy, transportation. One crucial component of ICS are Programmable Logic Controllers or PLCs. What makes PLCs a prime target for cyberattacks is their unique capacity to bridge the cyber and physical worlds. In 2021 a cyberattack that targeted the Colonial Pipeline ICS caused fuel shortages across several US states. Thus, it is worth asking: What are the attacks that adversaries can leverage to exploit PLCs? What are the available fortifications that can be used to ensure PLCs remain secure? In this research project, we conduct the first wide-scale systematization of knowledge that categorizes both cyber-attacks and defense- focused approaches for PLCs. Our methodology considers criteria such as attack complexity and defense effectiveness and considers an updated model of the attack surfaces of the PLC. We apply our methodology to several research papers from the past 20 years with the aim to discover trends and patterns. Preliminary results show that there are important research gaps. For example, we found that there are far more attack methods than defense methods. This leaves many attacks unchallenged. Properly identifying and addressing these research gaps may lead to new defense methods for previously unknown vulnerabilities, thus ultimately preventing the occurrence of future cyberattacks affecting vital infrastructure.Item Comparison of growth rates of larval Atlantic croaker collected near Corpus Christi and Galveston(2022-04) Weigand, Angelina; Geist, Simon; McAskill, Shannan; Bromschwig, MichelleDuring their early life stages, larval fish are vulnerable to a variety of physical, biological, and environmental processes. The ability of larval fish to successfully capture prey items affects their body condition, growth rates, and ultimately survivorship. Previous studies on the larval diets of M. undulatus collected from October to November 2017 at two distinct locations Galveston, TX and Corpus Christi, TX showed significantly different diets at the two locations at the family level taxonomic resolution of prey items. The goal of this study was to determine if the M. undulatus between the two locations also have a difference in condition and growth rates that may be related to differences in diets and localized prey availability. Larvae for this study were collected approximately two to two and a half months following Hurricane Harvey, which may have changed the water quality which affects the growth of larval fish. Therefore, this study will also assess differences in environmental parameters between the two locations to determine the potential effects of the Hurricane. For that otoliths were extracted from larval M. undulatus and use otolith increment growth analyses to investigate the differences in their growth rates. The samples were divided into different categories including catch date, size class, and catch site. The two size classes that the study focuses on are 5.0-6.99 mm and 7.0-8.99 mm. By extracting, mounting, polishing, and measuring the otoliths from the collected samples, we are able to determine the growth rate and the age of the fish and expect to see differences between locations that may be caused by diet differences and water quality.Item Abundance of bottlenose dolphins (tursiops truncatus) in Texas coastal bend(2022-04) Wilkins, Allison; Orbach, Dara N.Bottlenose dolphins (Tursiops truncatus) are the only species of marine mammal residing in the Texas Coastal Bend and have been specifically identified as imperiled by the National Oceanic and Atmospheric Administration. It has been almost 40 years since research has been published on the local population of bottlenose dolphins. In recent decades, the Texas Coastal Bend has substantially expanded in industrial growth and the Port of Corpus Christi is the third largest port in crude oil exportation in the U.S.A. The Corpus Christi Shipping Channel is also undergoing continual dredging to widen and deepen the channel to attract more commercial and industrial developments. With increasing and rapid changes and associated threats, it is important to monitor the local population of bottlenose dolphins and quantify how they are impacted by anthropogenic disturbance to inform policymakers for conservation mitigation. The population abundance of dolphins inhabiting the Texas Coastal Bend was determined by counting the number of animals based on unique markings. Photographs were captured of the individually distinctive dorsal fins of dolphins from a research vessel during 45 survey days since 2018. Photographs were subjected to quality control checks, cropped, matched by a minimum of two researchers, and scored based on quality. Preliminary results show that the current population of bottlenose dolphins consists of over 1,300 individuals, indicating a substantial population growth from the 593 dolphins reported in 1983. Findings from this study and additional photo- identification surveys will provide insights on the stability of the population that can be used as baseline data for conservation, including if dolphins are year-round residents and frequently inhabit areas of high vessel traffic.Item Sinking/suspended particles and zooplankton interactions in eastern tropical north pacific oxygen deficient zone revealed by δ15n-amino acids(2022-04) Lee, Charlotte; Mnich, Alanna; Catala, Fernando Contreras; García de León, Francisco Javier; Sánchez-Velasco, Laura; Baca, Jesus; McMullan, Esme; Mcallister, Marysa; Tran, Dat; Shaws, Catherine; Altabet, Mark; Zhang, LinPhotosynthesis by phytoplankton at the surface ocean fixes atmospheric carbon dioxide into organic matters that sink to the deep ocean in the form of particles. The composition and flux of particles could be affected by microbial degradation and consumption and repackaging by zooplankton. Within the oxygen deficient zones (ODZs), the zooplankton abundance is greatly reduced and oxygen is absent as electron acceptors for aerobic degradation of organic matters. Elevated biomass of zooplankton was found just below the lower ODZ boundary, presumably due to the higher availability of sinking particles for feeding. However, there is a lack of observations that could establish the link between sinking/suspended particles and zooplankton in the ODZs. A better understanding of sinking/suspended particles and zooplankton dynamics through ODZs is essential for evaluating the carbon export to the deep ocean, as ODZ is expected to expand due to the current warming climate. Sinking/suspended particles and zooplankton samples were collected at the eastern tropical north Pacific ODZ (14N, 104W) at various depths in December 2020. 15N of phenylalanine ( 15NPhe) and glutamic acid ( 15NGlu), the canonical source and trophic amino acid, are analyzed to assess the N isotope baseline and trophic positions (TPGlu-Phe) of these samples. 15NPhe and 15NGlu of surface suspended particles were 3.50‰ and 10.57‰ respectively, yielding a TPGlu-Phe of 1.48 that indicates the input of both phytoplankton and zooplankton materials to the suspended particle pool. Little enrichment in 15N of Glu was found between the suspended particles collected from the surface and below the lower boundary of ODZ (~1‰). This suggests limited trophic processing of sinking particles through the ODZ before zooplankton disaggregates them into suspended particles below the ODZ, which is in agreement with the slower sinking flux attenuation rate previously observed in ODZs.Item Corals thriving in dynamic environments may hold key insights into future coral reefs(2022-04) Epps, Ashleigh; Bruce, Morgan N.; Gates, Maryssa; Fifer, James; Davies, Sarah W; Bahr, KeishaThe coastal waters of Texas have dynamic environmental conditions and are heavily influenced by anthro- pogenic stressors, which are not conducive for corals. However, cryptic coral species (Astrangia poculata and Oculina diffusa) have been documented in this ecosystem, particularly within manmade channels on jetty rocks connecting the Gulf of Mexico and Corpus Christi Bay. This research explored the strategies that these corals utilize to survive with varying fluctuations in environmental conditions. Extensive in-water-field surveys were conducted in Packery Channel over one year to 1) identify observed corals 2) biologically char- acterize observed corals, 3) document environmental variability, 4) quantify zooplankton abundance, and 5) conduct coral tissue stable isotope analyses. Physical environmental data (e.g., turbidity, temperature, salinity, etc.) was measured weekly during each season (e.g., winter, spring, summer, and fall). Additionally, plankton abundance and diversity measurements were assessed within each season at the highest tide and the lowest tide of the full moon cycle. Corals were collected seasonally (total n=64). Results of this work revealed the species present are Astrangia poculata and Oculina diffusa and that these corals utilize both heterotrophy and autotrophy year-round to withstand extreme environmental conditions including large temperature (9.4-31.5°C) and turbidity (0-95.3 NTU) ranges. Stable isotope analyses suggest heterotrophy to be the dominant feeding mechanism year-round and autotrophy secondarily. Specifically, autotrophic contribution is more prominent during the summer and fall seasons than in the spring and winter seasons which correlates with the environmental data fluctuating the least in the summer and fall. Understanding the nutritional sources of corals in extreme environmental conditions could provide insights into potential phenotypic plasticity and adaptability to anthropogenic influence. Therefore, corals thriving in dynamic environments could provide researchers with the insight they need to understand coral adaptation amid rapidly changing environmental conditions.Item Analysis of coastal spatial-temporal systems of two species competition: Impact of the parameters of the system on species survival(2022-04) Wang, Youwen; Vasilyeva, Maria; Stepanov, Sergei; Sadovski, Alexey LThis presentation deals with the spatial-temporal dynamical models of two-species competition in 1D and 2D spaces. We have applied factor analysis to the results of tens of thousands of simulations with different combinations of parameters and initial conditions. Firstly, we have found that initial populations, if they are not too small, don’t affect equilibriums. Secondly, we have discovered that the diffusion rate has an impact on whether one or both species survives. Thirdly, the ratios of birthrates to competition parameters play significant role in which of two species survives.Item Characterizing a live shear-resistant (SR-) biofilm and its interaction with substrates of varying energy landscapes by digital holographic microscope in eChip microcosm(2022-04) Yi, Wenjun; Jalali- Mousavi, Maryam; Sheng, JianRecent studies reveal that biofilm can develop under severe flow shear (e.g. >10,000 s-1) and eventually becomes resistant to shear erosion. Additional anecdotal evidence suggests clear correlation between biofilm structure and its underlying substrate energy landscapes. In this study, we are to investigate systematically the effects of these two environmental factors on formation of SR-biofilm. Here, we present experimental techniques that combine a long-term ecology-on-a-chip (eChip) milli-/micro-fluidic platform to grow a live SR-biofilm and a digital holographic microscope (DHM). The newly improved eChip platform not only provides long-term well controlled environments to a live SR-biofilm but also allow DHM to track thousands of individual bacteria as they interact with the substrate. New milli-fluidics also enables the interchange of substrates (bottom wall) containing different energy landscapes (e.g. alternating hydrophilic-hydrophobic patterns). Model bacteria include E.coli.(AW405), P. aeruginosa (PAO1) and its 12 mutants. Apart from homogeneous hydrophobic and hydrophilic substates, six patterned substrates (i.e. hydrophilic micro-patches, microscale squares and stars, of 20um, 50um, 100um over hydrophobic background) are used. Interactions of bacteria with these substrates are conducted under two shear flow rates (0 &10ul/min). During each experiment, bacteria will be cultured in eChip platform and flow over the patterned substrates for observation. Thousands of individual bacteria are tracked simultaneously in 3D over 20min at 14.5 frames per seconds at 20X and subsequently 3D trajectories, from which changes of cell motility (swimming speed, reorientation motility, and their translational/angular dispersions) as well as their attachment rates, will be obtained. In this talk, we will first present the novel microfluidic approach and robust digital holography technique (recording & analysis) in measuring microbial motilities/particle mobilities, then followed by a kernel study of P. aeruginosa in quiescent fluid interacting with substrates.Item Test and evaluation of drones in order to determine personal space that drones can fly freely and safely(2022-04) St. John, Edward; Rangel, PabloWhen creating an algorithm to control a swarm of drones to complete the same or different tasks in unison, it is important to have maximum control and minimal safety risks during operation. The purpose of this research will be to test and evaluate how several different types of drones fly in order to calibrate the range that they may be able to react to one another and avoid collision. The term to determine the range at which a drone will sense an obstacle and react will be referred to as a ‘safety bubble’. The test and evaluation of flight parameters of each drone will be done using the Vicon Motion Capture Systems in the Collaborative Robots and Agents Lab (CORAL) to record values as several types of drones complete the task of taking off, flying to a destination, and landing. These values will be graphed and compared in MATLAB in order to determine the safety bubble size of each drone. If a drone is a newer model is will likely react with less time than an older model, therefore, it will likely have a smaller safety bubble. Sensor fusion will be used to determine the size of a safety bubble by having multiple layers of sensor arrays that will detect an object so the drone will have time to change course. When the drone senses an object it will react similarly to how a gas particle does during collision. The sensors will detect the obstacle and the drone will react by flying in the opposite direction, preventing collision.Item Requirement of gene transcription for experience-dependent long-term plasticity in the feeding neural circuit of an invertebrate model(2022-04) Mueller, Robert; Wainwright, Marcy; Mozzachiodi, RiccardoLong-term memory formation is known to generally require gene transcription (Kandel 2001). Previous research within the marine mollusk Aplysia revealed that repeated exposure to aversive stimuli induces a lasting enhancement of defensive responses, known as long-term sensitization (LTS). LTS is mediated, at least in part, by long-term increased excitability (LTIE) of sensory neurons (SN), which is known to depend on gene transcription (Byrne and Hawkins 2015). Repeated exposure to aversive stimuli also induces long- term feeding suppression (LTFS) via a long-term decreased excitability (LTDE) of decision-making neuron B51 (Shields-Johnson et al. 2013). However, it is unknown whether B51 LTDE depends on transcription processes like those in the defensive circuits. Therefore, this study examines the molecular requirements for LTFS by determining whether B51 LTDE is transcription dependent. Actinomycin D (ACT-D) is being used to selectively inhibit gene transcription (Montarolo et al. 1986). This project utilizes a previously established in vitro preparation that includes the neural circuits responsible for LTS and LTFS. Electrical stimulation of afferent nerves from the body wall to mimic aversive training in vitro co-induces SN LTIE and B51 LTDE lasting 24 h (Weisz et al. 2017). Ongoing experiments utilize 4 groups: trained/vehicle, trained/ACT-D, untrained/vehicle, and untrained/ACT-D (Weisz et al. 2017). Statistical analysis is being conducted using the Kruskal-Wallis test (Farruggella et al. 2019). Current results indicate that ACT-D is effective in blocking the expression of SN LTIE, as previously shown (Montarolo et al. 1986). Regarding B51, although overall statistical significance across groups has not been reached yet, current findings show a trend that LTDE expressed in the trained/vehicle group is blocked in the trained/ACT-D group. If these results are confirmed statistically, they will demonstrate that ACT-D inhibits B51 LTDE, thus indicating that B51 LTDE requires transcription processes for long-term memory formation analogous to SN LTIE in the defensive circuits.Item The influence of grouping features on explainable artificial intelligence for a complex fog prediction deep learning model(2022-04) Krell, Evan; Kamangir, Hamid; Friesand, Josh; Judge, Julianna; Collins, Waylon; King, Scott A.; Tissot, PhilippeAdvances in machine learning have enabled modeling complex nonlinear relationships. High performance models are increasingly reliant on “black boxes” such as deep learning where it is impractical to determine why predictions are made. This limits the user’s trust in the model, motivating the field of eXplainable Artificial Intelligence (XAI) to provide tools to understand how models make decisions. XAI techniques are used to explain FogNet: a complex model for predicting coastal fog whose input is a raster of 384 atmospheric variable channels. XAI techniques struggle with feature correlations and interactions, making it challenging to explain FogNet whose data is highly correlated by design. For example, a group of 108 channels represents the lower atmosphere thermodynamic profile. This gradient is used by forecasters to predict fog but complicates XAI with strong spatial-wise and channel-wise autocorrelation. Grouping related features has been proposed to improve XAI accuracy. Here, XAI techniques are applied with features grouped at multiple levels of granularity. The coarsest is to divide the raster channels into five groups based on physical similarity. The second scheme is to treat each individual channel as a feature, and finally superpixels within each channel. To analyze the sensitivity of explanations on the feature grouping used, the more granular outputs are aggregated into the coarser groups. This allows direct comparison of, for example, channel-wise explanations when using channels as feature groups, and when using superpixels within those channels as groups. The results indicate that the choice of feature grouping scheme influences the explanations, which can make interpretation of XAI results challenging. However, there are also consistencies that emerge that provide confidence in certain aspects of the explanations. Combined with forecaster domain knowledge, we demonstrate using the XAI outputs to generate hypotheses that drive the next phase of model development.Item Physiological stress and health of dolphins in the Texas coastal bend(2022-04) Guinn, Makayla A.; Orbach, Dara N.Common bottlenose dolphins (Tursiops truncatus) are an important bioindicator species of ecosystem welfare and sustainability and generate critical economic capital annually through ecotourism in the Texas Coastal Bend (TCB). The TCB stock of dolphins has specifically been identified as imperiled by the National Oceanic and Atmospheric Administration due to the number of anthropogenic and natural disturbances they encounter, and proactive monitoring of TCB dolphins is a current management priority. Recent economic growth has supported large-scale coastal infrastructure initiatives, including the imminent construction of desalination plants within the TCB. Because common bottlenose dolphins are highly vulnerable to salinity changes, which can lead to infectious disease and mortality, it is critical to determine baseline health and stress levels before the construction of desalination plants in order to monitor physiological changes post- construction and to inform policymakers of environmental impact. In this study, we will assess physiological stress and health conditions in TCB bottlenose dolphins using a novel approach system. A drone will be flown over dolphins to measure the prevalence and severity of skin lesions, which are an indicator of compromised epidermal integrity, for the first time from an aerial perspective. Blubber samples will be collected from the same dolphins using a remote biopsy technique to measure stress hormone levels; this study will be the first to validate aldosterone in the blubber of bottlenose dolphins. The baseline health and stress data collected will be used to directly measure bottlenose dolphin susceptibility to environmental disturbances and will assist in the preservation of marine life in the TCB.