Physical Sciences and Mathematics Commons^™

Gaps And Rings In An Alma Survey Of Disks In The Taurus Star-Forming Region, Feng Long, Paola Pinilla, Gregory J. Herczeg, Daniel Harsono, Giovanni Dipierro, Ilaria Pascucci, Nathan Hendler, Marco Tazzari, Enrico Ragusa, Colette Salyk, Suzan Edwards, Giuseppe Lodato, Gerrit Van De Plas, Doug Johnstone, Yao Liu, Yann Boehler, Sylvie Cabrit, Carlo F. Manara, Francois Menard, Gijs D. Mulders, Brunella Nisini, William J. Fischer, Elisabetta Rigliaco, Andrea Banzatti, Henning Avenhaus, Michael Gully-Santiago

Astronomy: Faculty Publications

Rings are the most frequently revealed substructure in ALMA dust observations of protoplanetary disks, but their origin is still hotly debated. In this paper, we identify dust substructures in 12 disks and measure their properties to investigate how they form. This subsample of disks is selected from a high-resolution (∼ 0.1200) ALMA 1.33 mm survey of 32 disks in the Taurus star-forming region, which was designed to cover a wide range of sub-mm brightness and to be unbiased to previously known substructures. While axisymmetric rings and gaps are common within our sample, spiral patterns and high contrast azimuthal asymmetries are …

Relationships Between Social Network Characteristics, Alcohol Use, And Alcohol-Related Consequences In A Large Network Of First-Year College Students: How Do Peer Drinking Norms Fit In?, Graham T. Diguiseppi, Matthew K. Meisel, Sara G. Balestrieri, Miles Q. Ott, Melissa A. Clark, Nancy P. Barnett

Statistical and Data Sciences: Faculty Publications

A burgeoning area of research is using social network analysis to investigate college students' substance use behaviors. However, little research has incorporated students' perceived peer drinking norms into these analyses. The present study investigated the association between social network characteristics, alcohol use, and alcohol-related consequences among first-year college students (N 1,342; 81% of the first-year class) at one university. The moderating role of descriptive norms was also examined. Network characteristics and descriptive norms were derived from participants' nominations of up to 10 other students who were important to them; individual network characteristics included popularity (indegree), network expansiveness (outdegree), relationship reciprocity, …

Can Farmers Adapt To Higher Temperatures? Evidence From India, Vis Taraz

Economics: Faculty Publications

Projections suggest that the damages from climate change will be substantial for developing countries. Understanding the ability of households in these countries to adapt to climate change is critical in order to determine the magnitude of the potential damages. In this paper, I investigate the ability of farmers in India to adapt to higher temperatures. I use a methodology that exploits short-term weather fluctuations as well as spatial variation in long-run climate. Specifically, I estimate how damaging high temperatures are for districts that experience high temperatures more or less frequently. I find that the losses from high temperatures are lower …

A New Look At T Tauri Star Forbidden Lines: Mhd-Driven Winds From The Inner Disk, Min Fang, Ilaria Pascucci, Suzan Edwards, Uma Gorti, Andrea Banzatti, Mario Flock, Patrick Hartigan, Gregory J. Herczeg, Andrea K. Dupree

Astronomy: Faculty Publications

Magnetohydrodynamic (MHD) and photoevaporative winds are thought to play an important role in the evolution and dispersal of planet-forming disks. We report the first high-resolution (∆v ∼ 6 km s−1 ) analysis of [S II] λ4068, [O I] λ5577, and [O I] λ6300 lines from a sample of 48 T Tauri stars. Following Simon et al. (2016), we decompose them into three kinematic components: a high-velocity component (HVC) associated with jets, and a low-velocity narrow (LVC-NC) and broad (LVC-BC) components. We confirm previous findings that many LVCs are blueshifted by more than 1.5 km s−1 thus most likely trace a …

Dynamical Constraints On The Hr 8799 Planets With Gpi, Jason J. Wang, James R. Graham, Rebekah Dawson, Daniel Fabrycky, Robert J. De Rosa, Laurent Pueyo, Quinn Konopacky, Bruce Macintosh, Christian Marois, Eugene Chiang, S. Mark Ammons, Pauline Arriaga, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, Rene Doyon, Gaspard Duchêne, Thomas M. Esposito, Michael P. Fitzgerald, Katherine B. Follette, Benjamin L. Gerard, Stephen J. Goodsell, Alexandra Z. Greenbaum, Pascale Hibon, Li Wei Hung, Patrick Ingraham, Paul Kalas, James E. Larkin, Jérôme Maire, Franck Marchis, Kimberly Ward-Duong

Astronomy: Faculty Publications

The HR 8799 system uniquely harbors four young super-Jupiters whose orbits can provide insights into the system's dynamical history and constrain the masses of the planets themselves. Using the Gemini Planet Imager, we obtained down to one milliarcsecond precision on the astrometry of these planets. We assessed four-planet orbit models with different levels of constraints and found that assuming the planets are near 1:2:4:8 period commensurabilities, or are coplanar, does not worsen the fit. We added the prior that the planets must have been stable for the age of the system (40 Myr) by running orbit configurations from our posteriors …

U.S. College Students’ Social Network Characteristics And Perceived Social Exclusion: A Comparison Between Drinkers And Nondrinkers Based On Pastmonth Alcohol Use, Sara G. Balestrieri, Graham T. Diguiseppi, Matthew Meisel, Melissa A. Clark, Miles Q. Ott, Nancy P. Barnett

Statistical and Data Sciences: Faculty Publications

There is a general perception on college campuses that alcohol use is normative. However, nondrinking students account for 40% of the U.S. college population. With much of the literature focusing on intervening among drinkers, there has been less of a focus on understanding the nondrinker college experience. The current study has two aims: to describe the social network differences between nondrinkers and drinkers in a college setting, and to assess perceived social exclusion among nondrinkers. METHOD:First-year U.S. college students (n = 1,342; 55.3% female; 47.7% non-Hispanic White) were participants in a larger study examining a social network of one college …

How To Catch When Proxies Lie: Verifying The Physical Locations Of Network Proxies With Active Geolocation, Zachary Weinberg, Shinyoung Cho, Nicolas Christin, Vyas Sekar, Phillipa Gill

Computer Science: Faculty Publications

Internet users worldwide rely on commercial network proxies both to conceal their true location and identity, and to control their apparent location. Their reasons range from mundane to security-critical. Proxy operators offer no proof that their advertised server locations are accurate. IP-to-location databases tend to agree with the advertised locations, but there have been many reports of serious errors in such databases. In this study we estimate the locations of 2269 proxy servers from ping-time measurements to hosts in known locations, combined with AS and network information. These servers are operated by seven proxy services, and, according to the operators, …

Reflection On Evolutionary Decision Making With Goal Modeling Via Empirical Studies, Alicia M. Grubb

Computer Science: Faculty Publications

Goal models have long been used in academia without wide spread adoption in industry. If the fundamental purpose of goal models is to allow stakeholders to generate scenarios and ask 'what if' questions, then which parts of the process of model construction, analysis, and evolution benefit from and which are hindered by manual activities? The recent expansion of goal modelling to ask time-based questions further amplifies this issue because significant additional information is required from stakeholders. Through a series of empirical studies, we aim to isolate the processes of model construction, analysis, and evolution for the purpose of studying the …

Bloomingleaf: A Formal Tool For Requirements Evolution Over Time, Alicia M. Grubb, Marsha Chechik

Computer Science: Faculty Publications

Our previous work presented the Evolving Intentions framework, which specified how evolving qualitative goal models can be modeled and analyzed. Recent improvements to the framework allow for precise semantics of goal relationships with propagation of both evidence for and evidence against a goal's satisfaction (as in Tropos), and enables evaluation of evolution with absolute time (in addition to relative time). The reasoning is expressed as a constraint satisfaction problem. In this paper, we present BloomingLeaf, a new web-based tool that implements the new semantics. We showcase how the implementation and architecture of BloomingLeaf can be used to answer time-based questions.

Small Shelly Fossil Preservation And The Role Of Early Diagenetic Redox In The Early Triassic, Sara B. Pruss, Nicholas J. Tosca, Courcelle Stark

Geosciences: Faculty Publications

Minute fossils from a variety of different metazoan clades, collectively referred to as small shelly fossils, represent a distinctive taphonomic mode that is most commonly reported from the Cambrian Period. Lower Triassic successions of the western United States, deposited in the aftermath of the end-Permian mass extinction, provide an example of small shelly style preservation that significantly post-dates Cambrian occurrences. Glauconitized and phosphatized echinoderms and gastropods are preserved in the insoluble residues of carbonates from the Virgin Limestone Member of the Moenkopi Formation. Echinoderm plates, spines and other skeletal elements are preserved as stereomic molds; gastropods are preserved as steinkerns. …

Strategic Players For Identifying Optimal Social Network Intervention Subjects, Miles Q. Ott, John M. Light, Melissa A. Clark, Nancy P. Barnett

Statistical and Data Sciences: Faculty Publications

We present a method whereby social network ties are used to identify behavioral leaders who are situated in the network such that these individuals are: 1) able to influence other individuals who are in need of and most receptive to intervention, thereby optimizing the impact of the intervention; and 2) not embedded with ties to individuals that are likely to be behaviorally antagonistic to the intervention or that would compromise the optimal impact of intervention. In this study we developed a method that we call Strategic Players, which is a solution for identifying a set of players who are close …

Catalysis Of Stark-Tuned Interactions Between Ultracold Rydberg Atoms, A. L. Win, William Williams, T. J. Carroll, C. I. Sukenik

Physics: Faculty Publications

We have experimentally investigated a catalysis effect in the resonant energy transfer between ultracold ⁸⁵Rb Rydberg atoms. We studied the time dependence of the process, 34p+34p→34s+35s, and observed an enhancement of 34s state population when 34d state atoms are added. We have also performed numerical model simulations, which are in qualitative agreement with experiment and indicate that the enhancement arises from a redistribution of p-state atoms due to the presence of the d-state atoms.

Methodology To Adapt And Update A Life Cycle Cost Calculator For Your Institution: A Step-By-Step Guide, Breanna J. Parker, Alexander R. Barron

Year on Climate Change: Other Materials

This guide provides a methodology for adapting a life cycle cost (LCC) calculator to your institution. An LCC calculator can be used to examine the present and future costs of any expenditure and can include a proxy carbon price in its analysis. Adapting an existing tool saves time and resources when compared to building from scratch. It also provides the most accurate information by accounting for specifics of context, such as energy costs and the greenhouse gas emission rates of energy sources, which vary by region.

This guide outlines a five-step process for adapting an LCC calculator to match your …

A How-To Guide For The Smith College Proxy Carbon Life Cycle Cost Calculator, Breanna J. Parker, Alexander R. Barron, Susan Stratton Sayre

Year on Climate Change: Other Materials

Detailed written guide for using the LCC calculator for Smith College. A similar guide can be adapted for users of the calculator at your institution.

The Smith College Proxy Carbon Life Cycle Cost Calculator is a tool designed to include climate impacts in the evaluation of present and future costs of projects on campus. At the request of the Study Group on Climate Change, this Excel tool was developed as part of the implementation of a proxy carbon price at Smith College.

Monitoring Scene Understanders With Conceptual Primitive Decomposition And Commonsense Knowledge, Leilani H. Gilpin, Jamie C. Macbeth, Evelyn Florentine

Computer Science: Faculty Publications

Although there have been many key advancements in connecting text and perception, computer- generated image captions still lack common sense. As a first step towards constraining these perception mechanisms to commonsense judgment, we have developed reasonableness monitors: a wrapper interface that can explain if the descriptive output of an opaque deep neural network is plausible. These monitor a standalone system that uses careful dependency tracking, commonsense knowledge, and conceptual primitives to explain a perceived scene description to be reasonable or not. If such an explanation cannot be made, it is evidence that something unreasonable has been perceived. The development of …

Auxetics Abounding, Ciprian S. Borcea, Ileana Streinu

Computer Science: Faculty Publications

Auxetic behavior refers to lateral widening upon stretching. Although a structural origin for this rather counterintuitive type of deformation was often suggested, a theoretical understanding of the role of geometry in auxetic behavior has been a challenge for a long time. However, for structures modeled as periodic bar-and-joint frameworks, including atom-and-bond frameworks in crystalline materials, there is a complete geometric solution which opens endless possibilities for new auxetic designs. We construct a large family of three-dimensional auxetic periodic mechanisms and discuss the ideas involved in their design.

New Neilson Library Life Cycle Assessment Report, Thornton Tomasetti

The New Neilson Library

Life cycle assessment results for achieving credits for LEED v4 MRc1 Building Life-cycle Impact reduction credit and its Option 4: Whole building impact assessment.

Testing Quantum Electrodynamics In The Lowest Singlet State Of Neutral Beryllium-9, E. C. Cook, Alisha Daya Vira, E. Livernois, William Williams

Physics: Faculty Publications

We report spectroscopic results on the 2s2p¹P₁ state in neutral atomic beryllium-9. The absolute frequency for the center of gravity is determined to be 42 565.4501(13)  cm−1, a factor of 130 more precise than the previous experimental measurement. The result is in agreement with and a factor of 8 more precise than the current best theoretical estimate of 42 565.441(11)  cm−1, which was calculated including the effects of quantum electrodynamics. Because of the large natural linewidth of the transition, the hyperfine constants were not able to be extracted to high precision.

Direct Imaging Of The Hd 35841 Debris Disk: A Polarized Dust Ring From Gemini Planet Imager And An Outer Halo From Hst/Stis, Thomas M. Esposito, Gaspard Duchne, Paul Kalas, Malena Rice, Ilodie Choquet, Bin Ren, Marshall D. Perrin, Christine H. Chen, Pauline Arriaga, Eugene Chiang, Eric L. Nielsen, James R. Graham, Jason J. Wang, Robert J.De Rosa, Katherine B. Follette, S. Mark Ammons, Megan Ansdell, Vanessa P. Bailey, Travis Barman, Juan Sebastián Bruzzone, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, Rene Doyon, Michael P. Fitzgerald, Stephen J. Goodsell, Alexandra Z. Greenbaum, Pascale Hibon, Li Wei Hung, Patrick Ingraham, Quinn Konopacky, James E. Larkin, Kimberly Ward-Duong, Et Al

Astronomy: Faculty Publications

We present new high resolution imaging of a light-scattering dust ring and halo around the young star HD 35841. Using spectroscopic and polarimetric data from the Gemini Planet Imager in H-band (1.6 μm), we detect the highly inclined (i = 85°) ring of debris down to a projected separation of ∼12 au (∼0.″12) for the first time. Optical imaging from HST/STIS shows a smooth dust halo extending outward from the ring to >140 au (>1.″4). We measure the ring's scattering phase function and polarization fraction over scattering angles of 22°-125°, showing a preference for forward scattering and a polarization …

Thermobarometry Of The Moine And Sgurr Beag Thrust Sheets, Northern Scotland, Sarah E. Mazza, Calvin Mako, Richard D. Law, Mark J. Caddick, Maarten Krabbendam, John Cottle

Geosciences: Faculty Publications

In the Caledonides of northern Scotland temperatures of metamorphism (Tm) and deformation (Td) progressively increase structurally up section in the Moine thrust sheet at the foreland edge of the Scandian (mid Silurian) orogenic wedge. However, the thermal history of the structurally overlying, more hinterland positioned thrust sheets is less well known. This study focuses on determining Td and Tm for both the central/upper part of the Moine thrust sheet and the lower part of the overlying Sgurr Beag thrust sheets in the middle of the Northern Highlands Terrane. Preserved microstructures and quartz c-axis fabric opening angles in the Moine and …

The Potential For Indirect Negative Effects Of Exotic Insect Species On A Liverwort, Bazzania Trilobata (Lepidoziaceae), Mediated By The Decline Of A Foundation Tree Species, Tsuga Canadensis (Pinaceae), Michelle R. Jackson, Jesse Bellemare

Biological Sciences: Faculty Publications

In many ecological communities, the effects of exotic species are likely to extend beyond their direct interactions with natives, due to indirect effects. This dynamic might be particularly consequential in cases where invasive insects or other exotic herbivores target foundation plant species in the communities they invade. In this study at a site in western Massachusetts, we used experimental transplants to gauge the potential effects of a decline in the evergreen conifer Tsuga canadensis due to ongoing spread of two exotic insect pests on a liverwort, Bazzania trilobata, whose distribution is closely linked to dense stands of this conifer in …

Offline Signature Verification Via Structural Methods: Graph Edit Distance And Inkball Models, Paul Maergner, Nicholas Howe, Kaspar Riesen, Rolf Ingold, Andreas Fischer

Computer Science: Faculty Publications

For handwritten signature verification, signature images are typically represented with fixed-sized feature vectors capturing local and global properties of the handwriting. Graphbased representations offer a promising alternative, as they are flexible in size and model the global structure of the handwriting. However, they are only rarely used for signature verification, which may be due to the high computational complexity involved when matching two graphs. In this paper, we take a closer look at two recently presented structural methods for handwriting analysis, for which efficient matching methods are available: keypoint graphs with approximate graph edit distance and inkball models. Inkball models, …

Open Problems From Cccg 2017, Joseph O'Rourke

Computer Science: Faculty Publications

The following is a description of the problems presented on July 26th, 2017 at the open-problem session of the 29th Canad. Conf. Computational Geometry held at Carleton University, in Ottawa.

Static And Dynamic Properties Of Shell-Shaped Condensates, Kuei Sun, Karmela Padavić, Frances Yang, Smitha Vishveshwara, Courtney Lannert

Physics: Faculty Publications

Static, dynamic, and topological properties of hollow systems differ from those that are fully filled as a result of the presence of a boundary associated with an inner surface. Hollow Bose-Einstein condensates (BECs) naturally occur in various ultracold atomic systems and possibly within neutron stars but have hitherto not been experimentally realized in isolation on Earth because of gravitational sag. Motivated by the expected first realization of fully closed BEC shells in the microgravity conditions of the Cold Atomic Laboratory aboard the International Space Station, we present a comprehensive study of spherically symmetric hollow BECs as well as the hollowing …

Challenging The Estrangela / Serto Divide: Why The Standard Model Of Syriac Scripts Just Doesn't Work, Kristina Bush, Michael Philip Penn, R. Jordan Crouser, Nicholas Howe, Shuangxia Wu

Computer Science: Faculty Publications

As part of a larger digital paleography project, our team has assembled a database of tens of thousands of individual Syriac letters and letter data from 96% of extant early Syriac manuscripts that have a secure composition date. Long term, such data can help scholars develop more accurate ways to classify Syriac scripts. In the present article we use this data to illustrate just how frequently the most common way of categorizing Syriac scripts as either Estrangela or Serto does not accurately convey the ways early scribes actually wrote. In addition to challenging this “Standard Model” of Syriac scripts, the …

Mechanistic Studies Of Palladium-Catalyzed Aminocarbonylation Of Aryl Chlorides With Carbon Monoxide And Ammonia, Justin Y. Wang, Alexandra E. Strom, John F. Hartwig

Chemistry: Faculty Publications

Mechanistic information on a reliable, palladium-catalyzed aminocarbonylation of aryl chlorides with ammonia is reported. The reaction occurs with ethylene complex 1 as catalyst, and mechanistic information was gained by isolation of catalytic intermediates and kinetic measurements, including the first mechanistic data on the oxidative addition of aryl chloride to a palladium(0) complex in the presence of CO. Arylpalladium and phenacylpalladium halide intermediates were synthesized, and kinetic measurements of the formation and reactions of these intermediates were undertaken to determine the mechanism of the oxidative addition of aryl bromides and chlorides to a Pd(0) dicarbonyl compound in the presence of CO …

Construction Of Red Fox Chromosomal Fragments From The Short-Read Genome Assembly, Halie M. Rando, Marta Farré, Michael P. Robson, Naomi B. Won, Jennifer L. Johnson, Ronak Buch, Estelle R. Bastounes, Xueyan Xiang, Shaohong Feng, Shiping Liu, Zijun Xiong, Jaebum Kim, Guojie Zhang, Lyudmila N. Trut, Denis M. Larkin, Anna V. Kukekova

Computer Science: Faculty Publications

The genome of a red fox (Vulpes vulpes) was recently sequenced and assembled using next-generation sequencing (NGS). The assembly is of high quality, with 94X coverage and a scaffold N50 of 11.8 Mbp, but is split into 676,878 scaffolds, some of which are likely to contain assembly errors. Fragmentation and misassembly hinder accurate gene prediction and downstream analysis such as the identification of loci under selection. Therefore, assembly of the genome into chromosome-scale fragments was an important step towards developing this genomic model. Scaffolds from the assembly were aligned to the dog reference genome and compared to the alignment of …

Toward Unfolding Doubly Covered N-Stars, Hugo A. Akitaya, Brad Ballinger, Mirela Damian, Erik Demaine, Martin L. Demaine, Robin Flatland, Irina Kostitsyna, Jason S. Ku, Stephan Langerman, Joseph O'Rourke, Ryuhei Uehara

Computer Science: Faculty Publications

No abstract provided.

Contribution Of Benthic Processes To The Growth Of Ooids On A Low-Energy Shore In Cat Island, The Bahamas, Giulio Mariotti, Sara B. Pruss, Roger E. Summons, Sharon A. Newman, Tanja Bosak

Geosciences: Faculty Publications

Ooids are typically found in frequently reworked coastal sediments, and are thought to accrete by inorganic chemical precipitation around moving grains. The high organic content and the presence of biosignatures, however, suggest that ooids interact with benthic microbial communities. Here, we investigate the role of benthic processes on ooid growth on a leeward shore of Cat Island, The Bahamas. Polished ooids are present in the surf zone, whereas dull ooids and grapestones are present in microbially colonized sediments seaward of the surf zone. Wave hydrodynamics and sediment transport modeling suggest that microbially colonized sediments are mobilized at monthly time scales. …

Gpi Spectra Of Hr 8799 C, D, And E From 1.5 To 2.4 Μm With Klip Forward Modeling, Alexandra Z. Greenbaum, Laurent Pueyo, Jean Baptiste Ruffio, Jason J. Wang, Robert J.De Rosa, Jonathan Aguilar, Julien Rameau, Travis Barman, Christian Marois, Mark S. Marley, Quinn Konopacky, Abhijith Rajan, Bruce Macintosh, Megan Ansdell, Pauline Arriaga, Vanessa P. Bailey, Joanna Bulger, Adam S. Burrows, Jeffrey Chilcote, Tara Cotten, Rene Doyon, Gaspard Duchêne, Michael P. Fitzgerald, Katherine B. Follette, Benjamin Gerard, Stephen J. Goodsell, James R. Graham, Pascale Hibon, Li Wei Hung, Patrick Ingraham, Paul Kalas, James E. Larkin, Kimberly Ward-Duong, Et Al

Astronomy: Faculty Publications

We explore KLIP forward modeling spectral extraction on Gemini Planet Imager coronagraphic data of HR 8799, using PyKLIP, and show algorithm stability with varying KLIP parameters. We report new and re-reduced spectrophotometry of HR 8799 c, d, and e in the H and K bands. We discuss a strategy for choosing optimal KLIP PSF subtraction parameters by injecting simulated sources and recovering them over a range of parameters. The K1/K2 spectra for HR 8799 c and d are similar to previously published results from the same data set. We also present a K-band spectrum of HR 8799 e for the …