Tag: Cells R Us

Sensors and Materials for In-field Aqueous Analysis of Nitrate and Other Ions

Presenter(s): Ian Torrence—Biochemistry

Faculty Mentor(s): Sean Fontenot

Session 2: Cells R Us

Chemically sensitive field effect transistor (ChemFET) development have been well studied as ion- sensing chemical sensors . These devices are attractive to other chemical sensors due to their low cost, low power consumption, small size, and their compatibility with electronics . By applying an ion- selective material, typically a polymer, on the ChemFET it is possible to create an interfacial potential difference between the environment and the gate-oxide of the FET . This ion-selective material can be designed to ensure the potential difference is dependent only on the activity of a target analyte. Currently, there is a need for a real-time chemical sensor to detect both nitrate and ammonium concentrations in soil, dubbed “total-N” content of the soil, as described by the NSF grand challenge for closing the nitrate cycle . This is primarily to combat fertilizer runoff caused by over fertilization of crops resulting in high concentration of nitrate in lakes, rivers, and streams . My research shows promising results for two ChemFETs that are sensitive and selective for ammonium and nitrate respectively which can be measured simultaneously for real time nitrate sensing in aqueous systems .

Quantifying the spatial morphology of organic films through polarization- dependent imaging

Presenter(s): Madelyn Scott—Chemistry, Physics

Faculty Mentor(s): Kelly Wilson, Cathy Wong

Session 2: Cells R Us

Organic semiconducting materials are appealing, green alternatives to conventional semiconductors because they can be solution-processed into flexible films . However, solution-processing fabrication methods can be prone to morphological disorder, meaning that crystalline structures in the
film exhibit a variety of sizes and shapes . A large degree of morphological disorder inhibits the electronic functionality of a film for use in technological devices . Examining how film morphology varies with different deposition conditions allows us to connect the physical properties of organic semiconducting films to macroscopic perturbations in their formation environments . In this work, we used a homebuilt microscope to image the polarization-dependent absorption of organic films, and developed an image analysis software package to characterize their spatial morphology . A series of pictures are collected of the sample, rotating the polarizer between each image . For every pixel in the image, the absorption signal as a function of polarization angle is fit to a sinusoidal curve . These fits are employed to assign pixels in the image to discrete aggregate domains within the film . Quantitative domain metrics are computed to describe the morphology of the film . Several organic films are produced under different deposition conditions and their resulting morphologies are compared . By better understanding the relationship between deposition conditions and film formation, existing solution-processing techniques can be further controlled and refined to achieve target physical properties in organic semiconducting materials .

The influence of prenatal inflammation on postnatal maternal and infant behavior

Presenter(s): Nora Kearns—Biology

Faculty Mentor(s): Elinor Sullivan

Session 2: Cells R Us

A growing body of research suggests that prenatal nutrition and adiposity influence postnatal mental health outcomes for both mother and child . Inflammation, heavily influenced by maternal adiposity, has been identified as a potential biomarker for maternal depression and child behavioral dysfunction . The objective of this study was to test the hypothesis that maternal gestational inflammatory state predicts postnatal maternal and infant behavior, an effect moderated by pro- inflammatory cytokines and both pro and anti-inflammatory fatty acids . Maternal BMI was obtained from medical records, and maternal inflammatory state was assessed using plasma fatty acid and cytokine levels from 2nd and 3rd trimester blood draws . Maternal and infant behavior at 6 months postpartum was observed in a ten-minute videotaped free play interaction, which was evaluated using a well-validated coding scheme . Maternal BMI was positively correlated with a number of pro-inflammatory cytokines, and negatively correlated with anti-inflammatory omega-3 (n-3) fatty acids . Although no significant correlations were found between pro-inflammatory cytokines and negative maternal behaviors, Interleuken-10, an inflammation-regulating cytokine, was negatively associated with maternal sensitivity and positively associated with infant negative mood . Significant positive correlations were found between n-3 fatty acids and positive maternal behaviors such as sensitivity, positive regard for child, and animation . The beneficial effects of n-3 fatty acids did not translate to modifications in child behavior during free-play, although one inflammatory n-6 fatty acid was negatively correlated with child activity, as was the pro-inflammatory cytokine TNF-a, which was elevated in mothers with higher BMIs and mothers with ADHD . These results suggest that n-3 fatty acid consumption during pregnancy may attenuate the potential effects of inflammation and contribute to more optimal maternal mental health .

Altered Motor Response to Aversive and Attractive Odors as Potential Biomarker for Autism Spectrum Disorders

Presenter(s): Isabelle Cullen—Biology

Faculty Mentor(s): Matt Smear, David McCormick

Session 2: Cells R Us

Active sensing in olfaction is the modulation in sampling behavior (inhalation patterns, or sniffing)
to modulate sensory input . Previous studies in humans and mice observed pleasant odors are sampled at a higher inhalation magnitude, while aversive odors are sampled at lower magnitudes when compared to the clean air control . However, this sniffing modulation is not present in those with autism . Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social behaviors, communication skills, narrowed interests, and repetitive behaviors . Rozenkrantz et al . (2015) showed that children with ASD did not modulate sniffing behavior to aversive or attractive odors despite correctly identifying odors as pleasant or unpleasant, suggesting an innate altered motor response rather than perceptual differences . While studying the basis of this behavior in humans is limited, we can access the neural mechanism that underlies this behavior through transgenic mouse lines . With the support of the Smear lab, we will repeat Rozenkratz’s (2015) paradigm using Fragile X-Knockout mice to investigate the neurological mechanisms driving this phenomenon along with orofacial movements during olfaction . Due to COVID-19, data collection is limited, however, we have developed a small raspberry pi based system combined with a camera to track orofacial movements through the experiment . We then use Deep Lab Cut, an AI network, to extract facial patterns and movements of the nose during olfaction . This work will establish a behavioral paradigm for studying autism-related symptoms in mice, and will thus lay the groundwork for understanding the neural mechanisms underlying this disorder, which may serve as a potential biomarker to aid in earlier detection .

Hunting for prions: Using inheritance patterns in yeast cells to attribute epigenetic states to prion proteins

Presenter(s): Mikala Capage—Biology

Faculty Mentor(s): David Garcia

Session 2: Cells R Us

The Garcia Lab studies the effects of prion proteins on key biological processes using the budding yeast, Saccharomyces cerevisiae . Prions can influence a cell’s phenotype but are based on a heritable protein confirmation and not sequence differences in the nucleic genome . Prions are inherited through the cytoplasm in a pattern of “non-Mendelian” inheritance in which all the cell’s offspring inherit the phenotype caused by the prion . To order to continue to research the broader impacts of prion proteins on biology, it is necessary to identify new examples of them. Our lab recently identified five new candidate prions–of proteins that chemically modify RNA–in yeast that exhibited heritable growth traits after exposure to chemical stressors . To test if the previously observed growth traits inherit in a pattern consistent with a prion, this project uses central methods in
yeast genetics including tetrad dissections, cytoductions, and growth assays . This project has the potential to significantly add to the list of known yeast prions, particularly those involved in RNA biology . A broader understanding of how prions function in yeast will eventually help us transition to understanding the roles they may have in human cells . This is an ongoing project; presented here will be a description of the methods, preliminary and expected results, background information for each putative prion, and other aspects of this experiment .