Physical Sciences and Mathematics Commons^™

Dynamical Architectures Of S-Type Transiting Planets In Binaries. I. Target Selection Using Hipparcos And Gaia Proper Motion Anomalies, J. Zhang, L. M. Weiss, D. Huber, Eric L.N. Jensen, T. D. Brandt, K. Collins, D. M. Conti, H. Isaacson, P. Lewin, G. Marino, B. Massey, F. Murgas, E. Palle, D. J. Radford, H. M. Relles, G. Srdoc, C. Stockdale, T.-G. Tan, G. Wang

Physics & Astronomy Faculty Works

The effect of stellar multiplicity on planetary architecture and orbital dynamics provides an important context for exoplanet demographics. We present a volume-limited catalog of up to 300 pc of 66 stars hosting planets and planet candidates from Kepler, K2, and TESS with significant Hipparcos-Gaia proper motion anomalies, which indicates the presence of companions. We assess the reliability of each transiting planet candidate using ground-based follow-up observations, and find that the TESS Objects of Interest (TOIs) with significant proper anomalies show nearly four times more false positives due to eclipsing binaries compared to TOIs with marginal proper anomalies. In addition, we …

Novel Integrated Sachs-Wolfe Effect From Early Dark Energy, Tristan L. Smith, J. T. Giblin Jr., M. Amin, M. Gerhardinger, E. Florio, M. Cerep, S. Daniels

Physics & Astronomy Faculty Works

We study the nonlinear effects of minimally coupled, massless, cosmological scalar fields on the cosmic microwave background (CMB). These fields can exhibit postrecombination parametric resonance and subsequent nonlinear evolution leading to novel contributions to the gravitational potential. We compute the resulting contributions to the CMB temperature anisotropies through the time variation of the gravitational potential (i.e., the integrated Sachs-Wolfe (ISW) effect). We find that fields that constitute 5% of the total energy density and become dynamical at z_c ≃ 10⁴ can produce marginally observable ISW signals at multipoles ℓ ≃ 2000. Fields that become dynamical at earlier times …

Comparative Analysis Of Interacting Stepped Dark Radiation, N. Schöneberg, G. F. Abellán, T. Simon, A. Bartlett, Y. Patel, Tristan L. Smith

Physics & Astronomy Faculty Works

Models that address both the Hubble and S₈ tensions with the same mechanism generically cause a prerecombination suppression of the small scale matter power spectrum. Here we focus on two such models. Both models introduce a self-interacting dark radiation fluid scattering with dark matter, which has a step in its abundance around some transition redshift. In one model, the interaction is weak and with all of the dark matter whereas in the other it is strong but with only a fraction of the dark matter. The weakly interacting case is able to address both tensions simultaneously and provide a …

Separated Twins Or Just Siblings? A Multiplanet System Around An M Dwarf Including A Cool Sub-Neptune, M. Harris, D. Dragomir, I. Mireles, K. A. Collins, S. Ulmer-Moll, S. B. Howell, K. G. Stassun, G. Zhou, C. Ziegler, F. Bouchy, C. Briceño, D. Charbonneau, K. I. Collins, G. Fűűrész, N. M. Guerrero, J. M. Jenkins, Eric L.N. Jensen, M. H. K. Kristiansen, N. Law, M. Lendl, A. W. Mann, H. P. Osborn, S. N. Quinn, G. R. Ricker, R. P. Schwarz, S. Seager, E. B. Ting, R. Vanderspek, D. Watanabe, J. N. Winn

Physics & Astronomy Faculty Works

We report the discovery of two TESS sub-Neptunes orbiting the early M dwarf TOI-904 (TIC 261257684). Both exoplanets, TOI-904 b and c, were initially observed in TESS Sector 12 with twin sizes of 2.426 (+0.163)/(-0.157) and 2.167 (+0.130)/(-0.118) R_⊕, respectively. Through observations in five additional sectors in the TESS primary mission and the first and second extended missions, the orbital periods of the planets were measured to be 10.887 ± 0.001 and 83.999 ± 0.001 days, respectively. Reconnaissance radial velocity measurements (taken with EULER/CORALIE and SMARTS/CHIRON) and high-resolution speckle imaging with adaptive optics (obtained from SOAR/HRCAM and Gemini …

Assessing The Robustness Of Sound Horizon-Free Determinations Of The Hubble Constant, Tristan L. Smith, V. Poulin, T. Simon

Physics & Astronomy Faculty Works

The Hubble tension can be addressed by modifying the sound horizon (r_s) before recombination, triggering interest in early universe estimates of the Hubble constant, H₀, independent of r_s. Constraints on H₀ from an r_s-free analysis of the full shape BOSS galaxy power spectra within Λ CDM were recently reported and used to comment on the viability of physics beyond Λ CDM. Here we demonstrate that r_s-free analyses with current data depend on both the model and the priors placed on the cosmological parameters, such that Λ CDM analyses …

Homomorphism Obstructions For Satellite Maps, Allison N. Miller

Mathematics & Statistics Faculty Works

A knot in a solid torus defines a map on the set of (smooth or topological) concordance classes of knots in S³. This set admits a group structure, but a conjecture of Hedden suggests that satellite maps never induce interesting homomorphisms: we give new evidence for this conjecture in both categories. First, we use Casson-Gordon signatures to give the first obstruction to a slice pattern inducing a homomorphism on the topological concordance group, constructing examples with every winding number besides ± 1. We then provide subtle examples of satellite maps which map arbitrarily deep into the n-solvable filtration …

Approximate Confidence Distribution Computing, Suzanne Thornton, W. Li, M. Xie

Mathematics & Statistics Faculty Works

Approximate confidence distribution computing (ACDC) offers a new take on the rapidly developing field of likelihood-free inference from within a frequentist framework. The appeal of this computational method for statistical inference hinges upon the concept of a confidence distribution, a special type of estimator which is defined with respect to the repeated sampling principle. An ACDC method provides frequentist validation for computational inference in problems with unknown or intractable likelihoods. The main theoretical contribution of this work is the identification of a matching condition necessary for frequentist validity of inference from this method. In addition to providing an example of …

The Unusual M-Dwarf Warm Jupiter Toi-1899 B: Refinement Of Orbital And Planetary Parameters, A. S. J. Lin, J. E. Libby-Roberts, J. A. Alvarado-Montes, C. I. Cañas, S. Kanodia, T. Han, L. Hebb, Eric L.N. Jensen, S. Mahadevan, L. C. Powers, T. N. Swaby, J. Wisniewski, C. Beard, C. F. Bender, C. H. Blake, W. D. Cochran, S. A. Diddams, R. C. Frazier, C. Fredrick, M. Gully-Santiago, S. Halverson, S. E. Logsdon, M. W. Mcelwain, C. Morley, J. P. Ninan, J. Rajagopal, L. W. Ramsey, P. Robertson, A. Roy, C. Schwab, G. Stefánsson, D. J. Stevens, R. C. Terrien, J. T. Wright

Physics & Astronomy Faculty Works

TOI-1899 b is a rare exoplanet, a temperate warm Jupiter orbiting an M dwarf, first discovered by Cañas et al. (2020) from a TESS single-transit event. Using new radial velocities (RVs) from the precision RV spectrographs HPF and NEID, along with additional TESS photometry and ground-based transit follow-up, we are able to derive a much more precise orbital period of P = 29.090312 (+0.000036)/(-0.000035) days, along with a radius of R_p = 0.99 ± 0.03 R_j. We have also improved the constraints on planet mass, M_p = 0.67 ± 0.04 M_j, and eccentricity, which …

Toi-908: A Planet At The Edge Of The Neptune Desert Transiting A G-Type Star, F. Hawthorn, D. Bayliss, D. J. Armstrong, J. Fernández Fernández, A. Osborn, S. G. Sousa, V. Adibekyan, J. Davoult, K. A. Collins, Y. Alibert, S. C. C. Barros, F. Bouchy, M. Brogi, D. R. Ciardi, T. Daylan, E. Delgado Mena, O. D. S. Demangeon, R. F. Díaz, T. Gan, K. Horne, S. Hoyer, J. M. Jenkins, Eric L.N. Jensen, J. F. Kielkopf, V. Kostov, D. W. Latham, A. M. Levine, J. Lillo-Box, L. D. Nielsen, H. P. Osborn, G. R. Ricker, J. Rodrigues, N. C. Santos, R. P. Schwarz, S. Seager, J. Serrano Bell, A. Shporer, C. Stockdale, P. A. Strøm, P. Tenenbaum, S. Udry, P. J. Wheatley, J. N. Winn, C. Ziegler

Physics & Astronomy Faculty Works

We present the discovery of an exoplanet transiting TOI-908 (TIC-350153977) using data from TESS sectors 1, 12, 13, 27, 28, and 39. TOI-908 is a T = 10.7 mag G-dwarf (T_eff = 5626 ± 61 K) solar-like star with a mass of 0.950 ± 0.010 M⊙ and a radius of 1.028 ± 0.030 R⊙. The planet, TOI-908 b, is a 3.18 ± 0.16 R⊕ planet in a 3.18 d orbit. Radial velocity measurements from HARPS reveal TOI-908 b has a mass of approximately 16.1 ± 4.1 M⊕, resulting in a bulk planetary density of 2.7 (+0.2)/(-0.4)g cm⁻³. TOI-908 b …

Magnetic-Field-Driven Director Configuration Transitions In Radial Nematic Liquid Crystal Droplets, S. Ettinger, C. G. Slaughter, S. H. Parra, J. M. Kikkawa, Peter J. Collings, A. G. Yodh

Physics & Astronomy Faculty Works

We study the director configurations of nematic liquid crystal (NLC) droplets with homeotropic anchoring in a magnetic field and report observation of a magnetic-field-driven transition from a deformed radial to an axial-with-defect configuration. Magnetic-field-induced transitions in NLC droplets differ fundamentally from the traditional planar Freedericksz transition due to the spherical droplet geometry and resulting topological defect. This transition has been studied theoretically, but the director configurations and mechanism of defect evolution in an applied magnetic field have yet to be observed experimentally. To this end, we combine polarized optical microscopy with a variable electromagnet (≤ 1 T) for continuous observation …

On The Frequencies Of Circumbinary Discs In Protostellar Systems, D. Elsender, M. R. Bate, B. S. Lakeland, Eric L.N. Jensen, S. H. Lubow

Physics & Astronomy Faculty Works

We report the analysis of circumbinary (CB) discs formed in a radiation hydrodynamical simulation of star cluster formation. We consider both pure binary stars and pairs within triple and quadruple systems. The protostellar systems are all young (ages < 10⁵ yrs). We find that the systems that host a CB disc have a median separation of ≈11 au, and the median characteristic radius of the discs is ≈64 au. We find that 89 per cent of pure binaries with semimajor axes a < 1 au have a CB disc, and the occurrence rate of CB discs is bimodal with log-separation in pure binaries with a second peak at a ≈ 50 au. Systems with a > 100 au almost never have a CB disc. The median size of a CB disc is between ≈5 and 6 a depending on the order of the system, with higher order systems having larger discs relative to binary separation. We find the underlying distributions of mutual inclination between CB discs and binary orbits from …

Two Warm Neptunes Transiting Hip 9618 Revealed By Tess And Cheops, H. P. Osborn, G. Nowak, G. Hébrard, T. Masseron, J. Lillo-Box, E. Pallé, A. Bekkelien, H.-G. Florén, P. Guterman, A. E. Simon, V. Adibekyan, A. Bieryla, L. Borsato, A. Brandeker, D. R. Ciardi, A. Collier Cameron, K. A. Collins, J. A. Egger, D. Gandolfi, M. J. Hooton, D. W. Latham, M. Lendl, E. C. Matthews, A. Tuson, S. Ulmer-Moll, A. Vanderburg, T. G. Wilson, C. Ziegler, Y. Alibert, R. Alonso, G. Anglada, L. Arnold, J. Asquier, D. Barrado Y Navascues, W. Baumjohann, T. Beck, A. A. Belinski, W. Benz, F. Biondi, I. Boisse, X. Bonfils, C. Broeg, L. A. Buchhave, T. Bárczy, S. C. C. Barros, J. Cabrera, C. Cardona Guillen, I. Carleo, A. Castro-González, S. Charnoz, J. Christiansen, P. Cortes-Zuleta, S. Csizmadia, S. Dalal, M. B. Davies, M. Deleuil, X. Delfosse, L. Delrez, B.-O. Demory, A. B. Dunlavey, D. Ehrenreich, A. Erikson, R. B. Fernandes, A. Fortier, T. Forveille, L. Fossati, M. Fridlund, M. Gillon, R. F. Goeke, M. V. Goliguzova, E. J. Gonzales, M. N. Günther, M. Güdel, N. Heidari, C. E. Henze, S. Howell, S. Hoyer, J. I. Frey, K. G. Isaak, J. M. Jenkins, F. Kiefer, L. Kiss, J. Korth, P. F. L. Maxted, J. Laskar, A. Lecavelier Des Etangs, C. Lovis, M. B. Lund, R. Luque, D. Magrin, J. M. Almenara, E. Martioli, M. Mecina, J. V. Medina, D. Moldovan, M. Morales-Calderón, G. Morello, C. Moutou, F. Murgas, Eric L.N. Jensen, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, G. Peter, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, G. Ricker, O. D. S. Demangeon, A. M. S. Smith, N. Santos, G. Scandariato, S. Seager, S. G. Sousa, M. Steller, G. M. Szabó, D. Ségransan, N. Thomas, S. Udry, B. Ulmer, V. Van Grootel, R. Vanderspek, N. Walton, J. N. Winn

Physics & Astronomy Faculty Works

HIP 9618 (HD 12572, TOI-1471, TIC 306263608) is a bright (G = 9.0 mag) solar analogue. TESS photometry revealed the star to have two candidate planets with radii of 3.9 ± 0.044 R⊕ (HIP 9618 b) and 3.343 ± 0.039 R⊕ (HIP 9618 c). While the 20.77291 d period of HIP 9618 b was measured unambiguously, HIP 9618 c showed only two transits separated by a 680-d gap in the time series, leaving many possibilities for the period. To solve this issue, CHEOPS performed targeted photometry of period aliases to attempt to recover the true period of planet c, …

Bifurcation From Infinity With Oscillatory Nonlinearity For Neumann Problems, M. Chhetri, Nsoki Mavinga, R. Pardo

Mathematics & Statistics Faculty Works

We consider a sublinear perturbation of an elliptic eigenvalue problem with Neumann boundary condition. We give sufficient conditions on the nonlinear perturbation which guarantee that the unbounded continuum, bifurcating from infinity at the first eigenvalue, contains an unbounded sequence of turning points as well as an unbounded sequence of resonant solutions. We prove our result by using bifurcation theory combined with a careful analysis of the oscillatory behavior of the continuum near the bifurcation point.

Development And Reliability Analysis Of A Split-Administration Test Of The Math Epistemic Games Survey, Stephen Hackler, E. Elliott, M. Eichenlaub, A. M. Sweeney

Physics & Astronomy Faculty Works

The increasing and diversifying student enrollments in introductory physics courses make reliable, valid, and usable instruments for measuring student skills and gains ever more important. In introductory physics, in addition to teaching facts about mechanics, we also seek to teach our students the skills of “thinking like a physicist,” or expertise in and intuition for physical problem solving. How and when these expert, intuitive problem-solving skills emerge during a STEM education, or what the most effective teaching methods might be, are not certain. A facile survey to measure students’ “physics-thinking” skills in a pretest and post-test format is therefore desirable …

Discovery Of Extraordinary X-Ray Emission From Magnetospheric Interaction In The Unique Binary Stellar System Ε Lupi, B. Das, V. Petit, Y. Nazé, M. F. Corcoran, David H. Cohen, A. Biswas, P. Chandra, A. David-Uraz, M. A. Leutenegger, C. Neiner, H. Pablo, E. Paunzen, M. E. Shultz, A. Ud-Doula, G. A. Wade

Physics & Astronomy Faculty Works

We report detailed X-ray observations of the unique binary system ϵ Lupi, the only known short-period binary consisting of two magnetic early-type stars. The components have comparably strong, but anti-aligned magnetic fields. The orbital and magnetic properties of the system imply that the magnetospheres overlap at all orbital phases, suggesting the possibility of variable inter-star magnetospheric interaction due to the non-negligible eccentricity of the orbit. To investigate this effect, we observed the X-ray emission from ϵ Lupi, both near and away from periastron passage, using the Neutron Star Interior Composition Explorer mission (NICER) X-ray Telescope. We find that the system …

Development And Reliability Analysis Of A Split-Administration Test Of The Math Epistemic Games Survey, Stephen Hackler, E. Elliott, M. Eichenlaub, Alison M. Sweeney

Physics & Astronomy Faculty Works

The increasing and diversifying student enrollments in introductory physics courses make reliable, valid, and usable instruments for measuring student skills and gains ever more important. In introductory physics, in addition to teaching facts about mechanics, we also seek to teach our students the skills of “thinking like a physicist,” or expertise in and intuition for physical problem solving. How and when these expert, intuitive problem-solving skills emerge during a STEM education, or what the most effective teaching methods might be, are not certain. A facile survey to measure students’ “physics-thinking” skills in a pretest and post-test format is therefore desirable …

Toi-2498 B: A Hot Bloated Super-Neptune Within The Neptune Desert, G. Frame, D. J. Armstrong, H. M. Cegla, J. Fernández Fernández, A. Osborn, V. Adibekyan, K. A. Collins, E. Delgado Mena, S. Giacalone, J. F. Kielkopf, N. C. Santos, S. G. Sousa, K. G. Stassun, C. Ziegler, D. R. Anderson, S. C. C. Barros, D. Bayliss, C. Briceño, D. M. Conti, C. D. Dressing, X. Dumusque, P. Figueira, W. Fong, S. Gill, F. Hawthorn, J. M. Jenkins, Eric L.N. Jensen, M. A. F. Keniger, D. W. Latham, N. Law, J. J. Lissauer, A. W. Mann, L. D. Nielsen, H. Osborn, M. Paegert, S. Seager, R. P. Schwarz, A. Shporer, G. Srdoc, P. A. Strøm, J. N. Winn, P. J. Wheatley

Physics & Astronomy Faculty Works

We present the discovery and confirmation of a transiting hot bloated super-Neptune using photometry from the Transiting Exoplanet Survey Satellite (TESS) and the Las Cumbres Observatory Global Telescope (LCOGT) and radial velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS). The host star TOI-2498 is a V = 11.2, G-type (T_eff = 5905 ± 12 K) solar-like star with a mass of 1.12 ± 0.02 M_⊙ and a radius of 1.26 ± 0.04 R_⊙. The planet, TOI-2498 b, orbits the star with a period of 3.7 d, has a radius of …

Fucik Spectrum With Weights And Existence Of Solutions For Nonlinear Elliptic Equations With Nonlinear Boundary Conditions, Nsoki Mavinga, Q. A. Morris, S. B. Robinson

Mathematics & Statistics Faculty Works

We consider the boundary value problem −Δu + c(x)u = αm(x)u⁺ − βm(x)u⁻ + f(x,u), x∈Ω, (∂u)/(∂η) + σ(x)u = αρ(x)u⁺ − βρ(x)u⁻ + g(x,u), x∈∂Ω, where (α,β) ∈R2, c, m ∈ L^∞(Ω), σ, ρ ∈ L^∞(∂Ω), and the nonlinearities f and g are bounded …

Consistency Of Effective Field Theory Analyses Of The Boss Power Spectrum, T. Simon, P. Zhang, V. Poulin, Tristan L. Smith

Physics & Astronomy Faculty Works

We assess the robustness of Λ cold dark matter (Λ CDM) results from the full-shape analysis of BOSS power spectrum using the one-loop prediction of the effective field theory of large-scale structure (EFTofLSS). In former EFT analyses, the two public likelihoods pybird and class-pt lead to results in agreement only at the 1σ level, which may appear unsatisfactory given that they are derived from the same BOSS dataset and the same theory model. To identify the origin of the difference, we perform a thorough comparison of the various analyses choices made between the two pipelines. We find that most …

Strongly Invertible Knots, Equivariant Slice Genera, And An Equivariant Algebraic Concordance Group, Allison N. Miller, M. Powell

Mathematics & Statistics Faculty Works

We use the Blanchfield form to obtain a lower bound on the equivariant slice genus of a strongly invertible knot. For our main application, let K be a strongly invertible genus one slice knot with nontrivial Alexander polynomial. We show that the equivariant slice genus of an equivariant connected sum #ⁿ K is at least n/4. We also formulate an equivariant algebraic concordance group, and show that the kernel of the forgetful map to the classical algebraic concordance group is infinite rank.

Spinning Up A Daze: Tess Uncovers A Hot Jupiter Orbiting The Rapid Rotator Toi-778, J. T. Clark, B. C. Addison, J. Okumura, S. Vach, A. Errico, A. Heitzmann, J. E. Rodriguez, D. J. Wright, M. Clerté, C. J. Brown, T. Fetherolf, R. A. Wittenmyer, P. Plavchan, S. R. Kane, J. Horner, J. F. Kielkopf, A. Shporer, C. G. Tinney, L. Hui-Gen, S. Ballard, B. P. Bowler, M. W. Mengel, G. Zhou, A. S. Lee, A. David, J. Heim, M. E. Lee, V. Sevilla, N. E. Zafar, N. R. Hinkel, B. E. Allen, D. Bayliss, A. Berberyan, P. Berlind, A. Bieryla, F. Bouchy, R. Brahm, E. M. Bryant, J. L. Christiansen, D. R. Ciardi, K. N. Ciardi, K. A. Collins, J. Dallant, A. B. Davis, M. R. Díaz, C. D. Dressing, G. A. Esquerdo, J.-V. Harre, S. B. Howell, J. M. Jenkins, Eric L.N. Jensen, M. I. Jones, A. Jordán, D. W. Latham, M. B. Lund, J. Mccormac, L. D. Nielsen, J. Otegi, S. N. Quinn, D. J. Radford, G. R. Ricker, R. P. Schwarz, S. Seager, A. M. S. Smith, C. Stockdale, T.-G. Tan, S. Udry, R. Vanderspek, M. N. Günther, S. Wang, G. Wingham, J. N. Winn

Physics & Astronomy Faculty Works

NASA's Transiting Exoplanet Survey Satellite (TESS) mission has been uncovering a growing number of exoplanets orbiting nearby, bright stars. Most exoplanets that have been discovered by TESS orbit narrow-line, slow-rotating stars, facilitating the confirmation and mass determination of these worlds. We present the discovery of a hot Jupiter orbiting a rapidly rotating (v sin (i) = 35.1 ± 1.0 km s⁻¹) early F3V-dwarf, HD 115447 (TOI-778). The transit signal taken from Sectors 10 and 37 of TESS's initial detection of the exoplanet is combined with follow-up ground-based photometry and velocity measurements taken from Minerva-Australis, TRES, CORALIE, and …

Biophysical And X-Ray Crystallographic Characterizations On Complexes Of G-Quadruplexes With Small-Molecule Ligands, Ming Ye , '23

Senior Theses, Projects, and Awards

DNA can fold into G-quadruplexes (GQs), non-canonical secondary structures formed by stacking of G-tetrads. GQs are important in many biological processes, which makes them promising therapeutic targets for anticancer and antiviral drugs. Therefore, investigating the interaction between GQs and small-molecule ligands is important.

This thesis work surveyed the DNA-ligand interactions of over 20 GQ-ligand complexes via biophysical and X-ray crystallographic methods. Two sets of GQ-ligand complexes were characterized in detail. One set is a group of purine-only sequences, named GA, with a highly selective GQ ligand, N-methyl mesoporphyrin IX (NMM). The other set is a human telomeric sequence, Tel22, with …

Raise The Sun: A Qtbipoc Zine Workshop, Chris O. Stone , '23

Senior Theses, Projects, and Awards

No abstract provided.

Restructuring Pedagogical Norms In Stem: Towards A Socially And Ethically Conscious Approach To Computer Science Higher Education, Alison Kim , '23

Senior Theses, Projects, and Awards

No abstract provided.

Using Caulobacter Crescentus As A Model To Probe The Environmental Reactivity Of Silver Nanoparticles, Madeline M. Farber , '23

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are an increasingly common environmental pollutant with antimicrobial and antibacterial properties. The elucidation of their interaction with cellular membranes and subsequent mechanisms of toxicity are critical areas of research that need to be better understood in order to manage potential adverse environmental effects. This work investigates the interaction of AgNPs with large unilamellar vesicles (LUVs) as a model membrane system. Similar studies conducted by others in this field have largely been conducted with uncoated AgNPs, ignoring the effect of environmental conditions on the formation of an eco-corona on AgNPs. Thus, in this study, the spent medium (SM) …

Biophysical And Structural Characterization Of Non-Canonical Dna Structures, Paul C. Seth , '23

Senior Theses, Projects, and Awards

G-quadruplex (GQ) and i-motif (iM) non-canonical DNA structures can be formed by G- and C-rich sequences within the genome, respectively. GQ and iM DNA play important roles in different biological processes and are promising therapeutic targets. Recently, the first left-handed GQ (LHGQ) was discovered and much remains to be learned about the structure and function of LHGQ DNA.

In this thesis, we investigate the biophysical and structural behavior of two LHGQ-forming sequences from the human genome, from the Human Solute Carrier 1 (SLC) and nuclear receptor binding SET domain (NSD) genes. We found that flanking bases play an important role …

Method Design For Separation Of Non-Canonical Dna Structures Via Capillary Electrophoresis, Erin V. Chen , '23

Senior Theses, Projects, and Awards

G-quadruplex DNA structures are highly relevant subjects of biochemical study, implicated in human diseases and cancer. Conventional methods for G-quadruplex DNA structure separation are time-consuming, environmentally unfriendly, and low throughput. Thus, there is a pressing need for alternative methods of separation to be developed for G-quadruplex DNAs. Here we present work in designing a separation method using the capillary electrophoresis instrument. Capillary electrophoresis is a highly automated, reusable, and quantitative technique that separates analytes based on their size and charge. A capillary method for G-quadruplex separation would be a valuable analytical tool to supplement the biophysical methods available by addressing …

Using Capillary Electrophoresis To Quantify Competitive Binding Of Adsorbates To Silver Nanoparticles, Christopher D. Chung , '23

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are increasingly used commercially and medically due to their antimicrobial and antibacterial properties. With increased use comes increased release of AgNPs into the environment, and once released, AgNPs can form coronas with molecules ranging from biomolecules to proteins to natural organic matter (NOM). The molecules in the corona adsorb to the surface of the AgNPs, drastically altering their innate properties such as cytotoxicity and binding behavior. In this study, we characterize and quantify model AgNP-adsorbate systems by obtaining their relevant reaction parameters through three different affordable analytical techniques, including dynamic light scattering (DLS), UV-vis spectroscopy, and capillary …

Master Equation Modeling Of Prompt Dissociation Kinetics For Isoprene Derived Criegee Intermediates, Rory R. Schmidt , '23

Senior Theses, Projects, and Awards

Isoprene ozonolysis is a major atmospheric producer of atmospheric oxidizers and aerosols. This complex reaction pathway forms an exothermic cascade, where constant competition between bimolecular sinks, unimolecular isomerizations, and collisional relaxation dictate reactivity. This work focuses on two isoprene derived Criegee intermediates, methacrolein oxide (MACR oxide) and formaldehyde oxide (FO). While the potential energy surface of FO is well understood, the reactivity of energetically excited FO has not been explored in detail. MACR oxide isomerization and primary products have been adequately characterized and explored computationally and experimentally, but the potential energy surface beyond isopropenyl dioxirane has not received the same …

Toi-836: A Super-Earth And Mini-Neptune Transiting A Nearby K-Dwarf, F. Hawthorn, D. Bayliss, T. G. Wilson, A. Bonfanti, V. Adibekyan, Y. Alibert, S. G. Sousa, K. A. Collins, E. M. Bryant, A. Osborn, D. J. Armstrong, L. Abe, J. S. Acton, B. C. Addison, K. Agabi, R. Alonso, D. R. Alves, G. Anglada-Escudé, T. Bárczy, T. Barclay, D. Barrado, S. C. C. Barros, W. Baumjohann, P. Bendjoya, W. Benz, A. Bieryla, X. Bonfils, F. Bouchy, A. Brandeker, C. Broeg, D. J. A. Brown, M. R. Burleigh, M. Buttu, J. Cabrera, D. A. Caldwell, S. L. Casewell, D. Charbonneau, S. Charnoz, R. Cloutier, A. Collier Cameron, K. I. Collins, D. M. Conti, N. Crouzet, S. Czismadia, M. B. Davies, M. Deleuil, E. Delgado-Mena, L. Delrez, O. D. S. Demangeon, B.-O. Demoray, G. Dransfield, X. Dumusque, J. A. Egger, D. Ehrenreich, P. Eigmüller, A. Erickson, Z. Essack, A. Fortier, L. Fossati, M. Fridlund, M. N. Günther, M. Güdel, D. Gandolfi, H. Gillard, M. Gillon, C. Gnilka, M. R. Goad, R. F. Goeke, T. Guillot, A. Hadjigeorghiou, C. Hellier, B. A. Henderson, K. Heng, M. J. Hooton, K. Horne, S. B. Howell, S. Hoyer, J. M. Irwin, J. S. Jenkins, J. M. Jenkins, Eric L.N. Jensen, S. R. Kane, A. Kendall, J. F. Kielkopf, L. L. Kiss, G. Lacedelli, J. Laskar, D. W. Latham, A. Lecavalier Des Etangs, A. Leleu, M. Lendl, J. Lillo-Box, C. Lovis, D. Mékarnia, B. Massey, T. Masters, P. F. L. Maxted, V. Nascimbeni, L. D. Nielsen, S. M. O'Brien, G. Olofsson, H. P. Osborn, I. Pagano, E. Pallé, C. M. Persson, G. Piotto, P. Plavchan, D. Pollacco, D. Queloz, R. Ragazzoni, H. Rauer, I. Ribas, G. Ricker, D. Ségransan, S. Salmon, A. Santerne, N. C. Santos, G. Scandariato, F.-X. Schmider, R. P. Schwarz, S. Seager, A. Shporer, A. E. Simon, A. M. S. Smith, G. Srdoc, M. Steller, O. Suarez, G. M. Szabó, J. Teske, N. Thomas, R. H. Tilbrook, A. H. M. J. Triaud, S. Udry, V. Van Grootel, N. Walton, S. X. Wang, P. J. Wheatley, J. N. Winn, R. A. Wittenmyer, H. Zhang

Physics & Astronomy Faculty Works

We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (∼200 mas yr⁻¹), low metallicity ([Fe/H]≈−0.28) K-dwarf with a mass of 0.68 ± 0.05 M_⊙ and a radius of 0.67 ± 0.01 R⊙. We obtain photometric follow-up observations with a variety of facilities, and we use these data sets to determine that the inner planet, TOI-836 b, is a 1.70 ± 0.07 R_⊕ super-Earth in a 3.82-d orbit, placing it directly within the so-called …