Fluorescence anisotropy is a common measurement that helps provides important information on molecular mobility, solvent (environment) viscosity, or/and molecular size. Fluorescence anisotropy involves measurement of two orthogonally polarized light emission intensities. One of the common issues of fluorescence anisotropy measurements is that most optical detection systems respond differently to the parallel and perpendicular polarization of light. The challenging task is to estimate the calibration curve, often called as the instrumental G-factor (grating factor), a parameter indicates the contributions and/or distortion of the optical detection system to the parallel and/or perpendicular light polarization, so that one can correct their polarized emission intensity and obtain a proper fluorescence anisotropy result. Here we present novel techniques that we have been developed in our laboratory that help achieve the G-Factor curves for different instruments.

Despite living inside the Milky Way, we do not know well basic quantities such as its detailed chemical makeup at the level needed to fundamentally tie the Milky Way to studies of evolution in other galaxies. One key observable is the radial chemical abundance gradient. Open star clusters provide an age datable sample by which to measure this gradient. This measurement has previously been made using a diverse and regularly conflicting compilation of clusters from various literature studies. We present the first measurement using a large (462 stars in 28 open clusters), uniform sample of open clusters abundances. Our measurements show a general agreement with recent studies of the overall metallicity gradient, with a measured ∆ [Fe/H]/∆ RGC of -0.050 ± 0.004 dex/kpc. We also explore trends with distance from the galactic plane and cluster age, and finally investigate the existence of a "knee" in the overall abundance gradient, between 12-14 kpc, within the range suggested by previous work. We show strong evidence for this phenomenon.

Since a number of medical conditions require simultaneous treatment and diagnostics, the field of molecular therapeutics has recently turned to multifunctional approaches allowing for both therapy and biomedical imaging. A number of such molecular and nanoformulations are combined with fluorophores that allow for imaging of the delivery pathways of the drug in the visible. This is optimal for in-vitro or ex-vivo work, however, cannot be utilized well in-vivo. Thus, there is a need in nanoformulations optimized for both in-vitro and in-vivo studies. Graphene quantum dots, possessing intrinsic stable fluorescence in the visible and near-IR stand out as candidates for such complex application.

In this work, we for the first time produce biocompatible graphene quantum dots (GQDs) that exhibit multi-color emission both in visible and NIR possess a capability for biological pH sensing. These GQDs show the crystalline graphitic structure in TEM and average sizes of c.a. 5 nm beneficial for cellular internalization. They show no cytotoxicity even at high doses of 1 mg/mL that are used for imaging. As opposed to related structures such as graphene oxide and other graphene derivatives GQDs show high quantum yield in green (~500 nm) of ~50%. Near-IR emission at ~860 nm is located in the water window with reduced absorption and lower autofluorescence backgrounds providing a promising potential route for in-vivo studies. Emission of GQDs also depends on pH of the surrounding medium. The change in pH of as-prepared GQDs from 2.70 to 8.0 yields an increase of fluorescence intensity up to ~60%. Additionally, pH-dependent shifts of the spectral features allow differentiating between acidic cancerous and neutral healthy exocellular environments allowing to use GQDs for cancer detection. Therefore, our results indicate that GQDs have a significant potential in bio-applications because of their capacity for multi-color green/near-IR imaging for in-vitro/in-vivo studies, pH sensitivity, water solubility, low cytotoxicity and high capacity for cellular internalization.

Respiratory syncytial virus (RSV) is an extremely common viral respiratory infection that currently has no vaccine or treatment. One of the issues in developing a treatment has been that immune system responses in both humans and rats vary in their susceptibility to RSV across different age groups. In this study, we use a mathematical model to quantify the viral kinetics of RSV and analyze its relationship to age. After fitting the model to experimental data, six parameter values were determined and used to calculate the eclipse phase length, infection phase length, basic reproductive number, and infecting time. These values were compared by age and collection site. After running several statistical tests, there was no major trend with the parameter values in relation to either age or collection site. This result provides the foundations for further studies to explore how viral models can better represent RSV and understand the immune response in general.

Sagittarius (Sgr), a dwarf galaxy and satellite to the Milky Way, is currently being tidally torn apart. To study the chemistry of
Sgr, we have taken thousands of stellar spectra across the galaxy. We have analyzed the stellar component of Sgr member
stars by using The Cannon, a machine learning algorithm for determining stellar parameters (temperature, surface gravity, chemical
abundances) from stellar spectra. A subset of our stars have previously been observed as part of SDSS/APOGEE survey, at higher
quality, which allows us to use these spectra to train The Cannon so that we can obtain accurate abundances for the ~1,100 Sgr
member stars. This will allow us to confidently study the formation history and stellar evolution of Sgr, and place it within the
context of other dwarf galaxies.

In order to determine correct dosage of chemotherapy drugs, the effect of the drug must be properly quantified. There are two important values that characterize the effect of the drug: Emax is the maximum possible effect from a drug, and IC50 is the drug concentration where the effect diminishes by half. Currently, the technique used to measure these quantities gives estimates of the values that depend on the time at which the measurement is made. We use mathematical modeling to test a new method for measuring Emax and IC50 that gives estimates independent of measurement time. We fit treatment data from the literature to determine values for Emax and IC50 using mathematical models under two assumptions: that the drug reduces growth rate, or maximum number of cells. Our method produced IC50 estimates similar to estimates derived using current techniques. This work is intended to characterize the efficacy of anticancer drug treatments and determine the correct doses before trying those in patients to get the most effective therapeutic treatment.

Since the invention of on optical microscope various biological structures have been observed. Today we have a need to study subcellular structures and their dynamics. Here we encounter diffraction limit – two objects located closer than the half of the wavelength cannot be resolved as two distinct objects. Superresolution techniques have been developed to overcome this limit. They can be divided into two types: stochastic and deterministic. Stochastic ones (STORM, PALM) utilize natural ability of fluorescent molecules to blink. These methods require sparse labeling and significant amount of some time to acquire image. Deterministic ones (STED) utilize an additional pulsed light source to de-excite populated state. These methods require advanced technology. Our method is similar to deterministic superresolution techniques. We utilize long-living fluorescent dyes whose excited state population can be significantly enhanced by bursts of pulses. Enhancement occurs only when time delay between pulses within burst is shorter than the lifetime of the dye. By varying bursts and single pulses one may observe varying intensity of a dye, hence, achieve superresolution. Regular labeling methods become an advantage in this case, and such an experimental setup is not very different from conventional microscopy methods.

Respiratory coinfections are commonly found in patients hospitalized with influenza-like illness, but it is not clear whether these infections are more severe than single infections. Mathematical models can be used to help understand the dynamics of respiratory viral coinfections and their impact on the severity of the illness. Most models of viral infections use ordinary differential equations (ODEs) which reproduce the average behavior of the infection, however, they might not be accurate in predicting certain events because of the stochastic nature of the viral replication cycle. Stochastic simulations of single virus infections have shown that there is an extinction probability that depends on the size of the initial viral inoculum and parameters that describe virus-cell interactions. Thus the coexistence of viruses predicted by the ODEs might be difficult to observe in reality. In this work we develop a stochastic numerical implementation of the deterministic coinfection model using the Gillespie algorithm. Stochastic extinction probabilities for each viruses are calculated analytically and will be verified by stochastic simulations. Preliminary analyses of the model have showed that even if the two viruses are given the same initial growth rates, one virus can have higher probability of extinction than the other, namely competitive exclusion, opposing the coexistence cases predicted by the deterministic model.

Star clusters are key chemical and age tracers of Milky Way evolution. The use of star clusters to provide significant constraints on galaxy evolution, however, has been limited due to discrepancies between different studies. This work seeks to add additional open clusters into an existing large, uniform chemical abundance system. We analyze spectra of giant stars in 31 open clusters and, using a machine learning method called The Cannon, determine iron abundances. This uniform analysis is compared with previous results, and we present new chemical abundances of 12 star clusters.

Nanoscale zinc oxide (ZnO) is an inexpensive, widely accessible material used in numerous well-established and emerging applications due to the unique optoelectronic, structural and chemical properties as well as the variety of synthesis methods. One of these emerging applications of ZnO nanostructures is in the field of antibacterial tools. The antibacterial nature of this material is being actively investigated, yet the mechanisms behind remain largely unknown. Some studies indicate that there is an influence of the polarity of exposed ZnO surfaces on their antibacterial action. Crystalline ZnO forms hexagonal prisms due to an anisotropic hexagonal lattice, which in turn produces three primary surface types: Zn-polar, O-polar and nonpolar. The hexagonal faces of these prism-shaped crystals are polar while the rectangular surfaces are nonpolar. In this study we employ a hydrothermal chemical method for growing ZnO nanocrystals having tunable morphology with the aim of obtaining a reliable control of the predominant polarity of the exposed nanocrystalline surfaces. This in turn can serve as a platform to investigate mechanisms of antibacterial action. Using Scanning Electron Microscopy as a probe of the microcystal morphology we demonstrate that the predominant ZnO surface polarity can be affected through the variations in the chemical precursors of the hydrothermal process. The ability to control the morphology and prominent surface polarity of ZnO nanocrystals would allow us to investigate fundamental phenomena governing antibacterial characteristics of nanoscale ZnO.

Galaxies are not alone in space; often, they have neighboring galaxies with which they gravitationally interact. These interactions foster diverse characteristics, such as size, morphology, and color. This project studies the properties of galaxies in the context of their neighbors and environment. More specifically, I examine how the proximity between galaxies affects their evolution. I do this by exploring two samples: 1) galaxy pairs within a few galactic diameters of each other and 2) isolated galaxies separated from the next nearest galaxy by more than ~450,000 light years. Using existing Mapping Nearby Galaxies at Apache Point Observatory observations, part of the Sloan Digital Sky Survey IV, I determine the various types of ionization conditions present at different radii throughout each galaxy. Through these efforts, I explore which processes promote and hinder star formation within galaxies.

In vitro experiments are necessary to understand the processes driving viral infections and to develop antivirals and vaccines. However, experiments do not completely replicate the in vivo environment, and not all cell lines used in these experiments have the components necessary to support viral replication. In these cases, the missing elements are added to the medium to facilitate viral infections. Trypsin is an enzyme usually added to facilitate influenza infections in cell cultures. We use data from infections of influenza in different cell lines in the presence and absence of trypsin to parameterize a within-host mathematical model of influenza infection, and in this way understand the impact of trypsin in the dynamics of the infection.

Graphene is a promising material, due to its various inherent properties that will lead to better, smaller, faster, or flexible electronics. Graphene doesn’t exhibit optical emission, limiting its potential use in optoelectronics. However, graphene’s functional derivative Graphene Oxide (GO) maintains many of graphene’s properties and exhibits optical fluorescence emission in the visible/near-infrared, which makes it a candidate for novel applications such as optoelectronic transistors, light emitting diodes (LEDs), and solar cells. Therefore, finding a way to alter optical and electronic properties of GO will lead to more versatility and control among the aforementioned applications.
In this work, we studied the potential use of GO for microelectronic applications by observing the fluorescence of this material under the electric field. A dried GO/PVP film was subject up to 1.6 V/µm in between transparent conductive ITO electrodes resulting in observable quenching of fluorescence emission as the field was applied. The emission was further partially restored at 0 field. Additionally, microscopic flakes of graphene oxide deposited onto interdigitated 10 µm electrodes were subject to 100V/µm with no breakdown current detected. The fluorescence of individual flakes, observed via visible fluorescence microscopy, experienced substantial field-dependent quenching. In aqueous suspensions GO flakes exhibited electrophoretic migration signifying of charge separation. As a result of this work we suggest the potential of varying electronic and optical properties of graphene oxide via the electric field for the advancement and control over its optoelectronic device applications.

Within the Large Magellanic Cloud (LMC) galaxy, there are huge gaseous outflows that originated from violent supernovae explosions within this galaxy. Observing this outflow that is being kicked out from the LMC reveals that there is ionized gas present, which can be trace by using Ha emission. Using observations from the Wisconsin Ha Mapper (WHAM) in Chile, we are mapping out the Ha emission that is being kicked out of the LMC. In this project, I am removing the imprint of the Earth’s atmosphere in order to isolate the gas cloud. This will be used to determine how much gas is being thrown out of the galaxy. The more gas the galaxy loses, the more it would not be able to make stars in the future.

Interaction between galaxies is of critical importance to the formation and evolution of galaxies. We are conducting a study on both isolated and interacting low-mass galaxies to determine how their environment impacts their star-formation ability. We compare the features of gas and stars in isolated and interacting galaxies to examine the differences and similarities. The interaction-triggered star-formation activity will be further discussed to analyse how the internal properties of galaxies are influenced by the outer environment. This investigation is based on data from the fourth-generation Sloan Digital Sky Survey (SDSS-IV) / Mapping Nearby Galaxies at Apache Point Observatory (MaNGA), and is part of the project No.0285 in SDSS-IV.

Restitution describes a functional relationship between the action potential duration (APD) and the preceding diastolic interval (DI). It plays an important role in the function of the heart and is believed to determine the stability of heart rhythms. We investigate the effects of various antiarrhythmic drugs on dynamic and standard (S1-S2) restitution properties of APD of ventricular cells by using a canine ventricular cell model. The restitution hypothesis suggests that the slope of the restitution curve governs the transition to alternans, believed to be a precursor to the development of ventricular arrhythmias, particularly ventricular fibrillation (VF). Our study examines the slope of these restitution curves for three classes of drug to determine whether they are proarrhythmic or antiarrhythmic and to test the hypothesis for the prediction of alternans.

Respiratory tract infections are easily among the most diagnosed illnesses in modern medicine, especially involving infants and the elderly. Lower respiratory tract infections (LRTIs) are especially dangerous, often capable of producing lasting respiratory problems, increased hospitalization, and life-threatening illness. Our research is targeted towards uncovering a possible mechanism behind the spreading of LRTIs, in hopes of illuminating the connection between the diffusion of a given virus and the speed of mucous transfer within the respiratory tract. This project more specifically focuses on a system of nonlinear ordinary and partial differential equations which simulate the diffusion and advection driven dynamics of an infected respiratory system. With a more realistic spatiotemporal approach, we hope to find possible relationships between given rates of advection and diffusion, and the depth and duration of infection; a potential framework for understanding and preventing an otherwise refractory human affliction.

Terror Management Theory suggests that individuals rely on worldview defenses to contend with mortality concerns. Similarly, religious individuals bolster their specific beliefs in order to defend against the awareness of death. Five studies examined the intersection between quest religiosity (e.g., individuals whose religious worldviews are to doubt and question), worldview defense, and existential anxieties. We hypothesized that quest individuals have weakened religious beliefs causing greater death thought accessibility. Additionally, quest individuals should display heightened secular worldview striving following mortality salience and less certainty in their own religiosity.

The current research examined childhood environmental factors driving the development of an unpredictability schema (a mindset about the world and people in it as unpredictable) and how maintaining such a cognitive schema impacts body awareness and eating in the absence of hunger. In Study 1, low childhood SES, parenting inconsistency, and poor childhood neighborhood quality predicted development of an unpredictability schema, which predicted lower body awareness. In Study 2, participants with an unpredictability schema had lower body awareness, less mindful eating, and more self-reported eating in the absence of hunger. In Study 3, this pattern was conceptually replicated in a laboratory eating task demonstrating that participants with an unpredictability schema had lower body awareness, which predicted more eating in the absence of hunger. Together, these results suggest that development of an unpredictability schema may be an important predictor of low body awareness and eating in the absence of hunger. Although these outcomes may have historically promoted survival in unpredictable environments, they may contribute to obesity in contemporary food-rich environments.

Alternative seating is being used in classrooms around the nation, but its efficacy, especially for children that are not typically developing, has not been well-studied. This study looks at the effects of four different types of alternative seating on focus, problem solving, and feelings of calm and attentiveness as compared to a control condition. A chair was designed specifically for this study, in an attempt to better serve the needs of children with postural disorders and learning disabilities, as past research has shown that these children do not perform as well on therapy balls (Bagatell, Mirigliani, Patterson, Reyes, and Test, 2010). Two versions of this new chair were included in the study, as well as a normal chair with a weighted blanket, and a therapy ball. The participants were between five and nine years old and were asked to complete some executive functioning (EF) tasks and answer some questions about how they felt, while being videotaped so that observational data on their on-task behavior could be coded later. Meanwhile, their parents completed a questionnaire about their child, including some questions about any diagnoses the child might have. The data has not been fully analyzed yet, but I hypothesize that children with learning disabilities and postural issues will do much better on the EF tasks in the new chairs or with the weighted blanket than in the therapy ball or control condition. I anticipate that typically developing children will do better in all of the alternative seating options than in the control. Furthermore, I do not anticipate that one alternative seating option will be significantly better for every child. Rather, I hypothesize that results will vary from child to child, suggesting that each classroom should have a variety of alternative seating options, so that children can find the one that works best for them.

Alzheimer’s disease (AD) is a neurodegenerative disease currently affecting 5.5 million Americans. Moreover, the disease prevalence is expected to rise to 16 million by 2050. Characteristic AD pathology includes neurofibrillary tangles of tau protein and amyloid-beta (Aβ) plaques, which correspond with a deterioration of memory and cognition in patients afflicted with AD. Aβ is a peptide resulting from cleavage of amyloid precursor protein (APP) primarily present within neuronal cell membranes. The Aβ peptide aggregates into Aβ plaques throughout the AD brain, but a brain structure impacted heavily and early on in the disease progression is the hippocampus. As mice do not naturally form plaques, our lab utilizes the 5xFAD transgenic mouse, a model of familial AD, wherein genetic mutations result in plaques and allow us to study this human AD pathology in mice. Previous research from our lab has shown that 5xFAD mice that are chronically stressed through social isolation, as opposed to typical group housing, have an increased number of hippocampal Aβ plaques. The goal of the current project was to determine whether the stress-induced increase in Aβ plaques could be prevented through exposure to physical exercise alone, or to exercise and an enriched environment throughout the period of isolation. Two-month-old mice were housed in isolation, housed in isolation with an exercise wheel, or housed in isolation with an exercise wheel and an enriched environment. After 3 months, cognition was assessed through contextual fear conditioning, and brains were collected for hippocampal Aβ plaque counts.

Terror management research has shown that, following mortality salience (MS), death-thought accessibility (DTA) and distal worldview defenses appear after a delay. However, to date, delay times for DTA and worldview defense activation have differed, with longer periods being better. While the time course is theoretically understood (Arndt, Greenberg, & Cook, 2002), the optimal time to assess DTA and worldview defense seem to differ between studies. Two experiments varied the time following MS to see when DTA (Study 1) and worldview defense (Study 2) should ideally be assessed. Participants, in both studies, were assigned to either an MS or control prime and then to one of four delay conditions (0 min, 5 min, 10 min, & 15 min). In Study 1, DTA was assessed with a lexical decision task and demonstrated strongest DTA effects at 10 min. In Study 2, worldview defense was assessed using the Moral Transgression Scale, which demonstrated that worldview defense was strongest after at 15 min. The current research is important for better understanding how to appropriately conduct TMT research, as well as clarifying potential errors with other studies.

How do people judge the morality of groups who do negative behaviors for an admirable cause? For example, some participants responded to groups of people who disrupt abortion clinics, in order to save unborn children. In the current study, we tried to answer this question through the lens of Attitude Representation Theory (Lord & Lepper, 1999) and audience tuning (Higgins & Rholes, 1978). Previous research (Lu, 2015) has also shown that using an ART approach, self-radicalization can occur, such that participants can persuade themselves to adopt more extreme moral judgments than before. In this study, participants were presented with a fictitious scenario and then told to either write a letter to their best friend about why their friend should not join that group (embellishment) or about campus architecture (control group). Based on previous research, we hypothesized that those who write to their best friend will later rate the actions of a group as more immoral and want to see the group be punished more. The results provided support for both of our hypotheses since participants writing to their best friend demonstrated self-radicalization. The results suggest that moral judgments can be malleable based on context and circumstance. Broader implications will also be discussed.

Title:
The moderation of terror management effects in Broad Autism Phenotype (BAP) individuals

Authors:
Paulina Mozo, Kathryn England, Elidia Avelar, Caroline Pope, Nathania Davis, Arielle Cenin, & Cathy R. Cox

Abstract:
The Broad Autism Phenotype (BAP; Hurley, Losh, Parlier, Reznick, & Piven, 2007) describes individuals who show characteristics similar to those with autism spectrum disorder. For example, BAP individuals show aloof personality (e.g., a lack of interest in social interaction), rigid personality (e.g., little interest in change or difficulty with change) and pragmatic language problems (e.g., inability to engage in fluid, reciprocal conversation). According to terror management theory (TMT; Greenberg, Pyszczynski, & Solomon, 1986) people are motivated to mitigate the potential for anxiety inherent in the awareness of death so that these concerns do not bloom into debilitating terror. Individuals may do so through the use of three psychological defense mechanisms that together create an anxiety-buffering system: (a) cultural worldviews, (b) self-esteem, and (c) close relationships. Additionally, individuals show a greater accessibility of death-related thoughts following disruptions to their anxiety-buffering defense system (i.e., the DTA hypothesis; Hayes, Schimel, Arndt, & Faucher, 2010). Prior research has shown that individuals high in BAP rigidity demonstrate heightened death concerns and greater defensiveness following a mortality salience (MS) manipulation (Arrowood, Cox, & Ekas, 2016). Following this line of work, the current research aimed to examine the moderating effects of a sense of control on death-thought accessibility (DTA) in BAP individuals. To test this, participants were first asked to complete the BAPQ (Hurley et al., 2007) to assess the traits of aloofness, rigidity, and pragmatic language problems. Following previous research (e.g., Landau et al., 2011; Maxfield et al., 2007; Schimel, Greenberg, & Martens, 2003), participants completed a word search puzzle as the mortality salience (MS) manipulation. Specifically, in the death condition, seven death-related words (i.e., death, dead, decay, die, funeral, burial, & corpse) were embedded as they searched for neutral target words. Then, participants were randomly assigned to a control-prime writing task (i.e., full control, no control, vs. neutral). Finally, all participants completed the word-fragment completion task to measure DTA (Greenberg et al., 1986). The task presented 25 word fragments, 6 of which could be completed with a neutral or death-related word (e.g., COFF_ _ could be completed as either COFFIN or COFFEE), and DTA score was calculated as the total number of death-related word completions. A hierarchical multiple regression was performed to examine the effects of mortality salience, control, and BAP on death-thought accessibility. The results showed a significant three-way interaction between MS, control, and BAP rigidity on DTA scores. Specifically, this study provided evidence that priming individuals high in BAP rigidity with a sense of control buffered the effects of mortality salience. Given that parents of children with ASD experience greater accessibility of death-related thoughts, as compared to parents of typically developing children (Cox, Eaton, Ekas, & Van Enkevort, 2015), the current work provides a potential solution to buffer the effects of mortality salience in this population.

Human speech production and grammatical organization of language is controlled primarily by the left hemisphere of the brain. Broca’s area is a specialized area in the left frontal cortex that is responsible for our ability to construct grammatically correct sentences. Songbirds are studied as an animal model for understanding human language production. Our research sought to explore whether the neural control of birdsong syntax of the Bengalese finch is also lateralized; if so, the Bengalese finch would provide a good animal model to further study syntax generation in humans. To investigate this question, we recorded the birdsongs of 10 different Bengalese finches; then, the HVC (letters used as proper name) brain region, an area thought to control birdsong syntax, was lesioned in either the right hemisphere or the left hemisphere for each bird. Birdsong was then recorded for five months following the surgery. Song syllables were coded and analyzed to measure the syntactic structure of the song. The birdsongs were grouped into a right lesion group and a left lesion group, and they were compared based on three measures of song syntax; sequence stereotypy, sequence consistency, and sequence linearity were measured at each time point. HVC lesion initially disrupted song syntax, but song syntax recovered. There was no significant difference between the left and right lesion groups. When looking at individual time points, the right lesion group seemed to initially lose more syntactic control four days after surgery, but the group differences were non-significant. Overall, the two groups follow a similar trend of recovery. Our results suggest that the HVC control of Bengalese finch song syntax is not lateralized as it is in human speech. The recovery of song syntax following brain injury suggests that other areas of the brain contribute to the generation of syntactic structure of the Bengalese finch song.