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Swarthmore College

2016

Articles 1 - 26 of 26

Full-Text Articles in Physical Sciences and Mathematics

Probing A Panoply Of Curvaton-Decay Scenarios Using Cmb Data, Tristan L. Smith, D. Grin Nov 2016

Probing A Panoply Of Curvaton-Decay Scenarios Using Cmb Data, Tristan L. Smith, D. Grin

Physics & Astronomy Faculty Works

In the curvaton scenario, primordial curvature perturbations are produced by a second field that is subdominant during inflation. Depending on how the curvaton decays [possibly producing baryon number, lepton number, or cold dark matter (CDM)], mixtures of correlated isocurvature perturbations are produced, allowing the curvaton scenario to be tested using cosmic microwave background (CMB) data. Here, a full range of 27 curvaton-decay scenarios is compared with CMB data, placing limits on the curvaton fraction at decay, rD, and the lepton asymmetry, ξlep. If baryon number is generated by curvaton decay and CDM before (or vice versa), these limits imply specific …

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An ‘Analytic Dynamical Magnetosphere’ Formalism For X-Ray And Optical Emission From Slowly Rotating Magnetic Massive Stars, S. P. Owocki, A. Ud-Doula, J. O. Sundqvist, V. Petit, David H. Cohen, R. H. D. Townsend Nov 2016

An ‘Analytic Dynamical Magnetosphere’ Formalism For X-Ray And Optical Emission From Slowly Rotating Magnetic Massive Stars, S. P. Owocki, A. Ud-Doula, J. O. Sundqvist, V. Petit, David H. Cohen, R. H. D. Townsend

Physics & Astronomy Faculty Works

Slowly rotating magnetic massive stars develop ‘dynamical magnetospheres’ (DMs), characterized by trapping of stellar wind outflow in closed magnetic loops, shock heating from collision of the upflow from opposite loop footpoints, and subsequent gravitational infall of radiatively cooled material. In 2D and 3D magnetohydrodynamic (MHD) simulations, the interplay among these three components is spatially complex and temporally variable, making it difficult to derive observational signatures and discern their overall scaling trends. Within a simplified, steady-state analysis based on overall conservation principles, we present here an ‘analytic dynamical magnetosphere’ (ADM) model that provides explicit formulae for density, temperature, and flow speed …

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Towards A Reverse Newman’S Theorem In Interactive Information Complexity, Joshua Brody, H. Buhrman, M. Koucký, B. Loff, F. Speelman, N. Vereshchagin Nov 2016

Towards A Reverse Newman’S Theorem In Interactive Information Complexity, Joshua Brody, H. Buhrman, M. Koucký, B. Loff, F. Speelman, N. Vereshchagin

Computer Science Faculty Works

Newman’s theorem states that we can take any public-coin communication protocol and convert it into one that uses only private randomness with but a little increase in communication complexity. We consider a reversed scenario in the context of information complexity: can we take a protocol that uses private randomness and convert it into one that only uses public randomness while preserving the information revealed to each player? We prove that the answer is yes, at least for protocols that use a bounded number of rounds. As an application, we prove new direct-sum theorems through the compression of interactive communication in …

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Kelt-17b: A Hot-Jupiter Transiting An A-Star In A Misaligned Orbit Detected With Doppler Tomography, G. Zhou, J. E. Rodriguez, K. A. Collins, T. Beatty, T. Oberst, T. M. Heintz, K. G. Stassun, D. W. Latham, R. B. Kuhn, A. Bieryla, M. B. Lund, J. Labadie-Bartz, R. J. Siverd, D. J. Stevens, B. S. Gaudi, J. Pepper, L. A. Buchhave, J. Eastman, K. Colón, P. Cargile, D. James, J. Gregorio, P. A. Reed, Eric L.N. Jensen, David H. Cohen, K. K. Mcleod, T. G. Tan, R. Zambelli, D. Bayliss, J. Bento, G. A. Esquerdo, P. Berlind, M. L. Calkins, K. Blancato, M. Manner, C. Samulski, C. Stockdale, P. Nelson, D. Stephens, I. Curtis, J. Kielkopf, B. J. Fulton, D. L. Depoy, J. L. Marshall, R. Pogge, A. Gould, M. Trueblood, P. Trueblood Nov 2016

Kelt-17b: A Hot-Jupiter Transiting An A-Star In A Misaligned Orbit Detected With Doppler Tomography, G. Zhou, J. E. Rodriguez, K. A. Collins, T. Beatty, T. Oberst, T. M. Heintz, K. G. Stassun, D. W. Latham, R. B. Kuhn, A. Bieryla, M. B. Lund, J. Labadie-Bartz, R. J. Siverd, D. J. Stevens, B. S. Gaudi, J. Pepper, L. A. Buchhave, J. Eastman, K. Colón, P. Cargile, D. James, J. Gregorio, P. A. Reed, Eric L.N. Jensen, David H. Cohen, K. K. Mcleod, T. G. Tan, R. Zambelli, D. Bayliss, J. Bento, G. A. Esquerdo, P. Berlind, M. L. Calkins, K. Blancato, M. Manner, C. Samulski, C. Stockdale, P. Nelson, D. Stephens, I. Curtis, J. Kielkopf, B. J. Fulton, D. L. Depoy, J. L. Marshall, R. Pogge, A. Gould, M. Trueblood, P. Trueblood

Physics & Astronomy Faculty Works

We present the discovery of a hot Jupiter transiting the V = 9.23 mag main-sequence A-star KELT-17 (BD+14 1881). KELT-17b is a ${1.31}_{-0.29}^{+0.28}\,{M}_{{\rm{J}}}$, ${1.525}_{-0.060}^{+0.065}\,{R}_{{\rm{J}}}$ hot-Jupiter in a 3.08-day period orbit misaligned at −115fdg9 ± 4fdg1 to the rotation axis of the star. The planet is confirmed via both the detection of the radial velocity orbit, and the Doppler tomographic detection of the shadow of the planet during two transits. The nature of the spin–orbit misaligned transit geometry allows us to place a constraint on the level of differential rotation in the host star; we find that KELT-17 is consistent with …

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Improved Compressive Sensing Of Natural Scenes Using Localized Random Sampling, Victor J. Barranca, G. Kovačič, D. Zhou, D. Cai Aug 2016

Improved Compressive Sensing Of Natural Scenes Using Localized Random Sampling, Victor J. Barranca, G. Kovačič, D. Zhou, D. Cai

Mathematics & Statistics Faculty Works

Compressive sensing (CS) theory demonstrates that by using uniformly-random sampling, rather than uniformly-spaced sampling, higher quality image reconstructions are often achievable. Considering that the structure of sampling protocols has such a profound impact on the quality of image reconstructions, we formulate a new sampling scheme motivated by physiological receptive field structure, localized random sampling, which yields significantly improved CS image reconstructions. For each set of localized image measurements, our sampling method first randomly selects an image pixel and then measures its nearby pixels with probability depending on their distance from the initially selected pixel. We compare the uniformly-random and localized …

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Kepler-1647b: The Largest And Longest-Period Kepler Transiting Circumbinary Planet, V. B. Kostov, J. A. Orosz, W. F. Welsh, L. R. Doyle, D. C. Fabrycky, N. Haghighipour, B. Quarles, D. R. Short, W. D. Cochran, M. End, E. B. Ford, J. Gregorio, T. C. Hinse, H. Isaacson, J. M. Jenkins, Eric L.N. Jensen, S. Kane, I. Kull, D. W. Latham, J. J. Lissauer, G. W. Marcy, T. Mazeh, T. W. A. Müller, J. Pepper, S. N. Quinn, D. Ragozzine, A. Shporer, J. H. Steffen, G. Torres, G. Windmiller, W. J. Borucki Aug 2016

Kepler-1647b: The Largest And Longest-Period Kepler Transiting Circumbinary Planet, V. B. Kostov, J. A. Orosz, W. F. Welsh, L. R. Doyle, D. C. Fabrycky, N. Haghighipour, B. Quarles, D. R. Short, W. D. Cochran, M. End, E. B. Ford, J. Gregorio, T. C. Hinse, H. Isaacson, J. M. Jenkins, Eric L.N. Jensen, S. Kane, I. Kull, D. W. Latham, J. J. Lissauer, G. W. Marcy, T. Mazeh, T. W. A. Müller, J. Pepper, S. N. Quinn, D. Ragozzine, A. Shporer, J. H. Steffen, G. Torres, G. Windmiller, W. J. Borucki

Physics & Astronomy Faculty Works

We report the discovery of a new Kepler transiting circumbinary planet (CBP). This latest addition to the still-small family of CBPs defies the current trend of known short-period planets orbiting near the stability limit of binary stars. Unlike the previous discoveries, the planet revolving around the eclipsing binary system Kepler-1647 has a very long orbital period (~1100 days) and was at conjunction only twice during the Kepler mission lifetime. Due to the singular configuration of the system, Kepler-1647b is not only the longest-period transiting CBP at the time of writing, but also one of the longest-period transiting planets. With a …

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Planet Formation Imager (Pfi): Science Vision And Key Requirements, S. Kraus, J. D. Monnier, M. J. Ireland, G. Duchêne, C. Espaillat, S. Hönig, A. Juhasz, C. Mordasini, J. Olofsson, C. Paladini, K. Stassun, N. Turner, G. Vasisht, T. J. Harries, M. R. Bate, J.-F. Gonzalez, A. Matter, Z. Zhu, O. Panic, Z. Regaly, A. Morbidelli, F. Meru, S. Wolf, J. Ilee, J.-P. Berger, M. Zhao, Q. Kral, A. Morlok, A. Bonsor, D. Ciardi, S. R. Kane, K. Kratter, G. Laughlin, J. Pepper, S. Raymond, L. Labadie, R. P. Nelson, G. Weigelt, T. Ten Brummelaar, A. Pierens, R. Oudmaijer, W. Kley, B. Pope, Eric L.N. Jensen, A. Bayo, M. Smith, T. Boyajian, L. H. Quiroga-Nuñez, R. Millan-Gabet, A. Chiavassa, A. Gallenne, M. Reynolds, W.-J. De Wit, M. Wittkowski, F. Millour, P. Gandhi, C. Ramos Almeida, A. Alonso Herrero, C. Packham, M. Kishimoto, K. R. W. Tristram, J.-U. Pott, J. Surdej, D. Buscher, C. Haniff, S. Lacour, R. Petrov, S. Ridgway, P. Tuthill, G. Van Belle, P. Armitage, C. Baruteau, M. Benisty, B. Bitsch, S.-J. Paardekooper, C. Pinte, F. Masset, G. Rosotti Aug 2016

Planet Formation Imager (Pfi): Science Vision And Key Requirements, S. Kraus, J. D. Monnier, M. J. Ireland, G. Duchêne, C. Espaillat, S. Hönig, A. Juhasz, C. Mordasini, J. Olofsson, C. Paladini, K. Stassun, N. Turner, G. Vasisht, T. J. Harries, M. R. Bate, J.-F. Gonzalez, A. Matter, Z. Zhu, O. Panic, Z. Regaly, A. Morbidelli, F. Meru, S. Wolf, J. Ilee, J.-P. Berger, M. Zhao, Q. Kral, A. Morlok, A. Bonsor, D. Ciardi, S. R. Kane, K. Kratter, G. Laughlin, J. Pepper, S. Raymond, L. Labadie, R. P. Nelson, G. Weigelt, T. Ten Brummelaar, A. Pierens, R. Oudmaijer, W. Kley, B. Pope, Eric L.N. Jensen, A. Bayo, M. Smith, T. Boyajian, L. H. Quiroga-Nuñez, R. Millan-Gabet, A. Chiavassa, A. Gallenne, M. Reynolds, W.-J. De Wit, M. Wittkowski, F. Millour, P. Gandhi, C. Ramos Almeida, A. Alonso Herrero, C. Packham, M. Kishimoto, K. R. W. Tristram, J.-U. Pott, J. Surdej, D. Buscher, C. Haniff, S. Lacour, R. Petrov, S. Ridgway, P. Tuthill, G. Van Belle, P. Armitage, C. Baruteau, M. Benisty, B. Bitsch, S.-J. Paardekooper, C. Pinte, F. Masset, G. Rosotti

Physics & Astronomy Faculty Works

The Planet Formation Imager (PFI) project aims to provide a strong scientific vision for ground-based optical astronomy beyond the upcoming generation of Extremely Large Telescopes. We make the case that a breakthrough in angular resolution imaging capabilities is required in order to unravel the processes involved in planet formation. PFI will be optimised to provide a complete census of the protoplanet population at all stellocentric radii and over the age range from 0.1 to ~100 Myr. Within this age period, planetary systems undergo dramatic changes and the final architecture of planetary systems is determined. Our goal is to study the …

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Kelt-10b: The First Transiting Exoplanet From The Kelt-South Survey - A Hot Sub-Jupiter Transiting A V=10.7 Early G-Star, R. B. Kuhn, J. E. Rodriguez, K. A. Collins, M. B. Lund, R. J. Siverd, K. D. Colón, J. Pepper, K. G. Stassun, P. A. Cargile, D. J. James, K. Penev, G. Zhou, D. Bayliss, T. G. Tan, I. A. Curtis, S. Udry, D. Segransan, D. Mawet, S. Dhital, J. Soutter, R. Hart, B. Carter, B. S. Gaudi, G. Myers, T. G. Beatty, J. D. Eastman, D. E. Reichart, J. B. Haislip, J. F. Kielkopf, A. Bieryla, D. W. Latham, Eric L.N. Jensen, T. E. Oberst, D. J. Stevens Jul 2016

Kelt-10b: The First Transiting Exoplanet From The Kelt-South Survey - A Hot Sub-Jupiter Transiting A V=10.7 Early G-Star, R. B. Kuhn, J. E. Rodriguez, K. A. Collins, M. B. Lund, R. J. Siverd, K. D. Colón, J. Pepper, K. G. Stassun, P. A. Cargile, D. J. James, K. Penev, G. Zhou, D. Bayliss, T. G. Tan, I. A. Curtis, S. Udry, D. Segransan, D. Mawet, S. Dhital, J. Soutter, R. Hart, B. Carter, B. S. Gaudi, G. Myers, T. G. Beatty, J. D. Eastman, D. E. Reichart, J. B. Haislip, J. F. Kielkopf, A. Bieryla, D. W. Latham, Eric L.N. Jensen, T. E. Oberst, D. J. Stevens

Physics & Astronomy Faculty Works

We report the discovery of KELT-10b, the first transiting exoplanet discovered using the KELT-South telescope. KELT-10b is a highly inflated sub-Jupiter mass planet transiting a relatively bright V = 10.7 star (TYC 8378-64-1), with Teff = 5948 ± 74 K, log g = 4.319_{-0.030}^{+0.020} and [Fe/H] = 0.09_{-0.10}^{+0.11}, an inferred mass M★ = 1.112_{-0.061}^{+0.055} M☉ and radius R★ = 1.209_{-0.035}^{+0.047} R☉. The planet has a radius Rp = 1.399_{-0.049}^{+0.069} RJ and mass Mp = 0.679_{-0.038}^{+0.039} MJ. The planet has an eccentricity consistent with zero and a semi-major axis a …

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Compressive Sensing Reconstruction Of Feed-Forward Connectivity In Pulse-Coupled Nonlinear Networks, Victor J. Barranca, D. Zhou, D. Cai Jun 2016

Compressive Sensing Reconstruction Of Feed-Forward Connectivity In Pulse-Coupled Nonlinear Networks, Victor J. Barranca, D. Zhou, D. Cai

Mathematics & Statistics Faculty Works

Utilizing the sparsity ubiquitous in real-world network connectivity, we develop a theoretical framework for efficiently reconstructing sparse feed-forward connections in a pulse-coupled nonlinear network through its output activities. Using only a small ensemble of random inputs, we solve this inverse problem through the compressive sensing theory based on a hidden linear structure intrinsic to the nonlinear network dynamics. The accuracy of the reconstruction is further verified by the fact that complex inputs can be well recovered using the reconstructed connectivity. We expect this Rapid Communication provides a new perspective for understanding the structure-function relationship as well as compressive sensing principle …

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Pinning Susceptibility: The Effect Of Dilute, Quenched Disorder On Jamming, Amy Lisa Graves, Samer B. Nashed , '15, Elliot S. Padgett , '13, C. P. Goodrich, A. J. Liu, J. P. Sethna Jun 2016

Pinning Susceptibility: The Effect Of Dilute, Quenched Disorder On Jamming, Amy Lisa Graves, Samer B. Nashed , '15, Elliot S. Padgett , '13, C. P. Goodrich, A. J. Liu, J. P. Sethna

Physics & Astronomy Faculty Works

We study the effect of dilute pinning on the jamming transition. Pinning reduces the average contact number needed to jam unpinned particles and shifts the jamming threshold to lower densities, leading to a pinning susceptibility, χp. Our main results are that this susceptibility obeys scaling form and diverges in the thermodynamic limit as χp∝|ϕ−ϕ∞c|−γp where ϕ∞c is the jamming threshold in the absence of pins. Finite-size scaling arguments yield these values with associated statistical (systematic) errors γp=1.018±0.026(0.291) in d=2 and γp=1.534±0.120(0.822) in d=3. Logarithmic corrections raise the exponent in d=2 to close to the d=3 value, although the systematic errors …

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Rotamer-Restricted Fluorogenicity Of The Bis-Arsenical Reash, A. S. Walker, Paul R. Rablen, A. Schepartz Jun 2016

Rotamer-Restricted Fluorogenicity Of The Bis-Arsenical Reash, A. S. Walker, Paul R. Rablen, A. Schepartz

Chemistry & Biochemistry Faculty Works

Fluorogenic dyes such as FlAsH and ReAsH are used widely to localize, monitor, and characterize proteins and their assemblies in live cells. These bis-arsenical dyes can become fluorescent when bound to a protein containing four proximal Cys thiols—a tetracysteine (Cys4) motif. Yet the mechanism by which bis-arsenicals become fluorescent upon binding a Cys4 motif is unknown, and this nescience limits more widespread application of this tool. Here we probe the origins of ReAsH fluorogenicity using both computation and experiment. Our results support a model in which ReAsH fluorescence depends on the relative orientation of the aryl chromophore and the appended …

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Tunable Depletion Potentials Driven By Shape Variation Of Surfactant Micelles, M. D. Gratale, T. Still, C. Matyas, Z. S. Davidson, S. Lobel, Peter J. Collings, A. G. Yodh May 2016

Tunable Depletion Potentials Driven By Shape Variation Of Surfactant Micelles, M. D. Gratale, T. Still, C. Matyas, Z. S. Davidson, S. Lobel, Peter J. Collings, A. G. Yodh

Physics & Astronomy Faculty Works

Depletion interaction potentials between micron-sized colloidal particles are induced by nanometer-scale surfactant micelles composed of hexaethylene glycol monododecyl ether (C12E6), and they are measured by video microscopy. The strength and range of the depletion interaction is revealed to arise from variations in shape anisotropy of the surfactant micelles. This shape anisotropy increases with increasing sample temperature. By fitting the colloidal interaction potentials to theoretical models, we extract micelle length and shape anisotropy as a function of temperature. This work introduces shape anisotropy tuning as a means to control interparticle interactions in colloidal suspensions, and it shows how the interparticle depletion …

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Kelt-14b And Kelt-15b: An Independent Discovery Of Wasp-122b And A New Hot Jupiter, J. E. Rodriguez, K. D. Colón, K. G. Stassun, D. Wright, P. A. Cargile, D. Bayliss, J. Pepper, K. A. Collins, R. B. Kuhn, M. B. Lund, R. J. Siverd, G. Zhou, B. S. Gaudi, C. G. Tinney, K. Penev, T. G. Tan, C. Stockdale, I. A. Curtis, D. James, S. Udry, D. Segransan, A. Bieryla, D. W. Latham, T. G. Beatty, J. D. Eastman, G. Myers, J. Bartz, J. Bento, Eric L.N. Jensen, T. E. Oberst, D. J. Stevens May 2016

Kelt-14b And Kelt-15b: An Independent Discovery Of Wasp-122b And A New Hot Jupiter, J. E. Rodriguez, K. D. Colón, K. G. Stassun, D. Wright, P. A. Cargile, D. Bayliss, J. Pepper, K. A. Collins, R. B. Kuhn, M. B. Lund, R. J. Siverd, G. Zhou, B. S. Gaudi, C. G. Tinney, K. Penev, T. G. Tan, C. Stockdale, I. A. Curtis, D. James, S. Udry, D. Segransan, A. Bieryla, D. W. Latham, T. G. Beatty, J. D. Eastman, G. Myers, J. Bartz, J. Bento, Eric L.N. Jensen, T. E. Oberst, D. J. Stevens

Physics & Astronomy Faculty Works

We report the discovery of KELT-14b and KELT-15b, two hot Jupiters from the KELT-South survey. KELT-14b, an independent discovery of the recently announced WASP-122b, is an inflated Jupiter mass planet that orbits a $\sim {5.0}_{-0.7}^{+0.3}$ Gyr, V = 11.0, G2 star that is near the main sequence turnoff. The host star, KELT-14 (TYC 7638-981-1), has an inferred mass ${M}_{*}$ = ${1.18}_{-0.07}^{+0.05}$ M⊙ and radius ${R}_{*}$ = $1.37\pm -0.08$ R⊙, and has ${T}_{{\rm{eff}}}$ = ${5802}_{-92}^{+95}$ K, $\mathrm{log}{g}_{*}$ = ${4.23}_{-0.04}^{+0.05}$ and $[{\rm{Fe}}/{\rm{H}}]$ = 0.33 ± −0.09. The planet orbits with a period of 1.7100588 ± 0.0000025 days (T0 = 2457091.02863 ± 0.00047) …

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Possible Signatures Of Dissipation From Time-Series Analysis Techniques Using A Turbulent Laboratory Magnetohydrodynamic Plasma, D. A. Schaffner, Michael R. Brown, Ariel B. Rock , '16 May 2016

Possible Signatures Of Dissipation From Time-Series Analysis Techniques Using A Turbulent Laboratory Magnetohydrodynamic Plasma, D. A. Schaffner, Michael R. Brown, Ariel B. Rock , '16

Physics & Astronomy Faculty Works

The frequency spectrum of magnetic fluctuations as measured on the Swarthmore Spheromak Experiment is broadband and exhibits a nearly Kolmogorov 5/3 scaling. It features a steepening region which is indicative of dissipation of magnetic fluctuation energy similar to that observed in fluid and magnetohydrodynamic turbulence systems. Two non-spectrum based time-series analysis techniques are implemented on this data set in order to seek other possible signatures of turbulent dissipation beyond just the steepening of fluctuation spectra. Presented here are results for the flatness, permutation entropy, and statistical complexity, each of which exhibits a particular character at spectral steepening scales which can …

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Investigation Of The Interactions Between Pt(Ii) And Pd(Ii) Derivatives Of 5,10,15,20-Tetrakis (N-Methyl-4-Pyridyl) Porphyrin And G-Quadruplex Dna, Navin C. Sabharwal , '14, O. Mendoza, John Michael Nicoludis , '12, Thomas Ruan , '16, J.-L. Mergny, Liliya A. Yatsunyk Apr 2016

Investigation Of The Interactions Between Pt(Ii) And Pd(Ii) Derivatives Of 5,10,15,20-Tetrakis (N-Methyl-4-Pyridyl) Porphyrin And G-Quadruplex Dna, Navin C. Sabharwal , '14, O. Mendoza, John Michael Nicoludis , '12, Thomas Ruan , '16, J.-L. Mergny, Liliya A. Yatsunyk

Chemistry & Biochemistry Faculty Works

G-quadruplexes are non-canonical DNA structures formed by guanine-rich DNA sequences that are implicated in cancer and aging. Understanding how small molecule ligands interact with quadruplexes is essential both to the development of novel anticancer therapeutics and to the design of new quadruplex-selective probes needed for elucidation of quadruplex biological functions. In this work, UV–visible, fluorescence, and circular dichroism spectroscopies, fluorescence resonance energy transfer (FRET) melting assays, and resonance light scattering were used to investigate how the Pt(II) and Pd(II) derivatives of the well-studied 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP4) interact with quadruplexes formed by the human telomeric DNA, Tel22, and by the G-rich sequences …

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Enantiomerically Pure Planar Chiral N-Oxazolidinoyl Diene Tricarbonyl Iron(O) Complexes: Their Synthesis And Functionalization, Raundi E. Quevedo , '16 Apr 2016

Enantiomerically Pure Planar Chiral N-Oxazolidinoyl Diene Tricarbonyl Iron(O) Complexes: Their Synthesis And Functionalization, Raundi E. Quevedo , '16

Senior Theses, Projects, and Awards

Broadly, the goal of this research was to observe the scope of the molecules we could make, how effective the syntheses were, and what the broader outcomes were. One objective of this research was to observe how oxazolidinoyl iron tricarbonyl diene scaffolds could be used for the diastereoselective synthesis of molecules. To determine the substrate scope, we wanted to manipulate the group functionalization at the R1 and R2 side chain. We were able to incorporate the desired aldehyde both at the R1 and the R2 position, although subsequent manipulation was only successful at the R1 side chain. In addition to …

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Earth Systems Science As Civic Participation: An Approach To Youth Action Research For Social Change, Ciara Williams , '16 Apr 2016

Earth Systems Science As Civic Participation: An Approach To Youth Action Research For Social Change, Ciara Williams , '16

Senior Theses, Projects, and Awards

Just as environmental justice challenges dominant notions of "environment" that cannot account for connections between social and natural processes, earth systems science pursues connections between science and society, challenging a dominant discourse which asserts that both can be fully understood without the other. Grounding "environment" and "science" as socially situated concepts helps to foreground, in turn, the ways that race structures exposure to risk and the exercise of citizenship both nationally and globally. My thesis draws on these discourses while focusing on youth as citizens and civic participation through the creation of an elementary school science curriculum.

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The Gold Standard And Education Intervention Research: A Consideration Of Middle School Mathematics Interventions As A Particular Case, Sarah Nielsen , '16 Apr 2016

The Gold Standard And Education Intervention Research: A Consideration Of Middle School Mathematics Interventions As A Particular Case, Sarah Nielsen , '16

Senior Theses, Projects, and Awards

This thesis explores the benefits and drawbacks of various experimental designs, outcome measures, and specific methodological techniques in education intervention research. Through an analysis of nine top-tier journals in education, I describe which experimental designs and outcome measures are most commonly used in current middle school mathematics intervention research. Then, four case intervention studies with different experimental designs are closely examined. This discussion is juxtaposed with consideration of evaluation standards published by government agencies. Each study represents different discourses about the effectiveness of the intervention reported. Although the standards for intervention research no longer only promote randomized quantitative research, I …

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Physical Interpretations Of Permutation Entropy Scaling Analyses In Turbulent Fluids, Ariel Rock , '16 Apr 2016

Physical Interpretations Of Permutation Entropy Scaling Analyses In Turbulent Fluids, Ariel Rock , '16

Senior Theses, Projects, and Awards

We show that the methods permutation entropy and complexity analysis can be extended to a more robust tool by treating embedding delay as a freely varying parameter. We show that one can extract meaningful information about the nature turbulent systems when this extended analysis is applied to data taken from such systems. Furthermore, we find that this information agrees with information determined via conventional methodology, as well as providing new understanding about the systems analyzed.

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Stellar Activity And Exclusion Of The Outer Planet In The Hd 99492 System, S. R. Kane, B. Thirumalachari, G. W. Henry, N. R. Hinkel, Eric L. N. Jensen, T. S. Boyajian, D. A. Fischer, A. W. Howard, H. T. Isaacson, J. T. Wright Mar 2016

Stellar Activity And Exclusion Of The Outer Planet In The Hd 99492 System, S. R. Kane, B. Thirumalachari, G. W. Henry, N. R. Hinkel, Eric L. N. Jensen, T. S. Boyajian, D. A. Fischer, A. W. Howard, H. T. Isaacson, J. T. Wright

Physics & Astronomy Faculty Works

A historical problem for indirect exoplanet detection has been contending with the intrinsic variability of the host star. If the variability is periodic, it can easily mimic various exoplanet signatures, such as radial velocity (RV) variations that originate with the stellar surface rather than the presence of a planet. Here we present an update for the HD 99492 planetary system, using new RV and photometric measurements from the Transit Ephemeris Refinement and Monitoring Survey. Our extended time series and subsequent analyses of the Ca ii H&K emission lines show that the host star has an activity cycle of ~13 years. …

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The Mimes Survey Of Magnetism In Massive Stars: Introduction And Overview, G. A. Wade, C. Neiner, E. Alecian, J. H. Grunhut, V. Petit, B. De Batz, D. A. Bohlender, David H. Cohen, H. F. Heinrichs, O. Kochukhov, J. D. Landstreet, N. Manset, F. Martins, S. Mathis, M. E. Oksala, S. P. Owocki, T. Rivinius, M. E. Shultz, J. O. Sundqvist, R. H. D. Townsend, A. Ud-Doula, J.-C. Bouret, J. Braithwaite, M. Briquet, A. C. Carciofi, A. David-Uraz, C. P. Folsom, A. W. Fullerton, B. Leroy, W. L. F. Marcolino, A. F. J. Moffat, Y. Nazé, N. St Louis, M. Aurière, S. Bagnulo, J. D. Bailey, R. H. Barbá, A. Blazère, T. Böhm, C. Catala, J.-F. Donati, L. Ferrario, D. Harrington, I. D. Howarth, R. Ignace, L. Kaper, T. Lüftinger, R. Prinja, J. S. Vink, W. W. Weiss, I. Yakunin Feb 2016

The Mimes Survey Of Magnetism In Massive Stars: Introduction And Overview, G. A. Wade, C. Neiner, E. Alecian, J. H. Grunhut, V. Petit, B. De Batz, D. A. Bohlender, David H. Cohen, H. F. Heinrichs, O. Kochukhov, J. D. Landstreet, N. Manset, F. Martins, S. Mathis, M. E. Oksala, S. P. Owocki, T. Rivinius, M. E. Shultz, J. O. Sundqvist, R. H. D. Townsend, A. Ud-Doula, J.-C. Bouret, J. Braithwaite, M. Briquet, A. C. Carciofi, A. David-Uraz, C. P. Folsom, A. W. Fullerton, B. Leroy, W. L. F. Marcolino, A. F. J. Moffat, Y. Nazé, N. St Louis, M. Aurière, S. Bagnulo, J. D. Bailey, R. H. Barbá, A. Blazère, T. Böhm, C. Catala, J.-F. Donati, L. Ferrario, D. Harrington, I. D. Howarth, R. Ignace, L. Kaper, T. Lüftinger, R. Prinja, J. S. Vink, W. W. Weiss, I. Yakunin

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The MiMeS (Magnetism in Massive Stars) project is a large-scale, high-resolution, sensitive spectropolarimetric investigation of the magnetic properties of O- and early B-type stars. Initiated in 2008 and completed in 2013, the project was supported by three Large Program allocations, as well as various programmes initiated by independent principal investigators, and archival resources. Ultimately, over 4800 circularly polarized spectra of 560 O and B stars were collected with the instruments ESPaDOnS (Echelle SpectroPolarimetric Device for the Observation of Stars) at the Canada–France–Hawaii Telescope, Narval at the Télescope Bernard Lyot and HARPSpol at the European Southern Observatory La Silla 3.6 m …

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Kelt-4ab: An Inflated Hot Jupiter Transiting The Bright (V~10) Component Of A Hierarchical Triple, J. D. Eastman, T. G. Beatty, R. J. Siverd, J. M. O. Antognini, M. T. Penny, E. J. Gonzales, J. R. Crepp, A. W. Howard, R. L. Avril, A. Bieryla, K. Collins, B. J. Fulton, J. Ge, J. Gregorio, B. Ma, S. N. Mellon, T. E. Oberst, J. Wang, B. S. Gaudi, J. Pepper, K. G. Stassun, L. A. Buchhave, Eric L. N. Jensen, D. W. Latham, P. Berlind, M. L. Calkins, P. A. Cargile, K. D. Colón, S. Dhital, G. A. Esquerdo, J. A. Johnson, J. F. Kielkopf, M. Manner, Q. Mao, K. K. Mcleod, K. Penev, R. P. Stefanik, R. Street, R. Zambelli, D. L. Depoy, A. Gould, J. L. Marshall, R. W. Pogge, M. Trueblood, P. Trueblood Feb 2016

Kelt-4ab: An Inflated Hot Jupiter Transiting The Bright (V~10) Component Of A Hierarchical Triple, J. D. Eastman, T. G. Beatty, R. J. Siverd, J. M. O. Antognini, M. T. Penny, E. J. Gonzales, J. R. Crepp, A. W. Howard, R. L. Avril, A. Bieryla, K. Collins, B. J. Fulton, J. Ge, J. Gregorio, B. Ma, S. N. Mellon, T. E. Oberst, J. Wang, B. S. Gaudi, J. Pepper, K. G. Stassun, L. A. Buchhave, Eric L. N. Jensen, D. W. Latham, P. Berlind, M. L. Calkins, P. A. Cargile, K. D. Colón, S. Dhital, G. A. Esquerdo, J. A. Johnson, J. F. Kielkopf, M. Manner, Q. Mao, K. K. Mcleod, K. Penev, R. P. Stefanik, R. Street, R. Zambelli, D. L. Depoy, A. Gould, J. L. Marshall, R. W. Pogge, M. Trueblood, P. Trueblood

Physics & Astronomy Faculty Works

We report the discovery of KELT-4Ab, an inflated, transiting Hot Jupiter orbiting the brightest component of a hierarchical triple stellar system. The host star is an F star with ${T}_{{\rm{eff}}}$ = $6206\pm 75$ K, $\mathrm{log}g$ = $4.108\pm 0.014$, $[{\rm{Fe}}/{\rm{H}}]$ = $-{0.116}_{-0.069}^{+0.065}$, ${M}_{*}$ = ${1.201}_{-0.061}^{+0.067}$ $\;{M}_{\odot }$, and ${R}_{*}$ = ${1.603}_{-0.038}^{+0.039}$ $\;{R}_{\odot }$. The best-fit linear ephemeris is ${\mathrm{BJD}}_{\mathrm{TDB}}$ $\;=\;2456193.29157\pm 0.00021$ $\quad +\quad E(2.9895936\pm 0.0000048)$. With a magnitude of V ~ 10, a planetary radius of ${1.699}_{-0.045}^{+0.046}$ $\;{R}_{{\rm{J}}}$, and a mass of ${0.902}_{-0.059}^{+0.060}$ $\;{M}_{{\rm{J}}}$, it is the brightest host among the population of inflated Hot Jupiters (RP > 1.5RJ), making it a …

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A Disk-Based Dynamical Constraint On The Mass Of The Young Binary Dq Tau, I. Czekala, S. M. Andrews, G. Torres, Eric L.N. Jensen, K. G. Stassun, D. J. Wilner, D. W. Latham Feb 2016

A Disk-Based Dynamical Constraint On The Mass Of The Young Binary Dq Tau, I. Czekala, S. M. Andrews, G. Torres, Eric L.N. Jensen, K. G. Stassun, D. J. Wilner, D. W. Latham

Physics & Astronomy Faculty Works

We present new Atacama Large Millimeter/Submillimeter Array (ALMA) observations of CO J = 2-1 line emission from the DQ Tau circumbinary disk. These data are used to tomographically reconstruct the Keplerian disk velocity field in a forward-modeling inference framework, and thereby provide a dynamical constraint on the mass of the DQ Tau binary of {M}*={1.27}-0.27+0.46 {M}☉ . Those results are compared with an updated and improved orbital solution for this double-lined system based on long-term monitoring of its stellar radial velocities. Both of these independent dynamical constraints on the binary mass are in excellent agreement: …

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Grief And Gratitude, Lynne Steuerle Schofield Jan 2016

Grief And Gratitude, Lynne Steuerle Schofield

Mathematics & Statistics Faculty Works

No abstract provided.

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Efficient Image Processing Via Compressive Sensing Of Integrate-And-Fire Neuronal Network Dynamics, Victor J. Barranca, G. Kovačič, D. Zhou, D. Cai Jan 2016

Efficient Image Processing Via Compressive Sensing Of Integrate-And-Fire Neuronal Network Dynamics, Victor J. Barranca, G. Kovačič, D. Zhou, D. Cai

Mathematics & Statistics Faculty Works

Integrate-and-fire (I&F) neuronal networks are ubiquitous in diverse image processing applications, including image segmentation and visual perception. While conventional I&F network image processing requires the number of nodes composing the network to be equal to the number of image pixels driving the network, we determine whether I&F dynamics can accurately transmit image information when there are significantly fewer nodes than network input-signal components. Although compressive sensing (CS) theory facilitates the recovery of images using very few samples through linear signal processing, it does not address whether similar signal recovery techniques facilitate reconstructions through measurement of the nonlinear dynamics of an …

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Gravitational-Wave Cosmology Across 29 Decades In Frequency, P. D. Lasky, C. M.F. Mingarelli, Tristan L. Smith, J. T. Giblin Jr., E. Thrane, D. J. Reardon, R. Caldwell, M. Bailes, N.D. R. Bhat, S. Burke-Spolaor, S. Dai, J. Dempsey, G. Hobbs, M. Kerr, Y. Levin, R. N. Manchester, S. Osłowski, V. Ravi, P. A. Rosado, R. M. Shannon, R. Spiewak, W. Van Straten, L. Toomey, J. Wang, L. Wen, X. You, X. Zhu Jan 2016

Gravitational-Wave Cosmology Across 29 Decades In Frequency, P. D. Lasky, C. M.F. Mingarelli, Tristan L. Smith, J. T. Giblin Jr., E. Thrane, D. J. Reardon, R. Caldwell, M. Bailes, N.D. R. Bhat, S. Burke-Spolaor, S. Dai, J. Dempsey, G. Hobbs, M. Kerr, Y. Levin, R. N. Manchester, S. Osłowski, V. Ravi, P. A. Rosado, R. M. Shannon, R. Spiewak, W. Van Straten, L. Toomey, J. Wang, L. Wen, X. You, X. Zhu

Physics & Astronomy Faculty Works

Quantum fluctuations of the gravitational field in the early Universe, amplified by inflation, produce a primordial gravitational-wave background across a broad frequency band. We derive constraints on the spectrum of this gravitational radiation, and hence on theories of the early Universe, by combining experiments that cover 29 orders of magnitude in frequency. These include Planck observations of cosmic microwave background temperature and polarization power spectra and lensing, together with baryon acoustic oscillations and big bang nucleosynthesis measurements, as well as new pulsar timing array and ground-based interferometer limits. While individual experiments constrain the gravitational-wave energy density in specific frequency bands, …

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