Digital Commons Network^™

A Note On Solid Coloring Of Pure Simplicial Complexes, Joseph O'Rourke

Computer Science: Faculty Publications

We establish a simple generalization of a known result in the plane. The simplices in any pure simplicial complex in R^d may be colored with d+1 colors so that no two simplices that share a (d-1)-facet have the same color. In R² this says that any planar map all of whose faces are triangles may be 3-colored, and in R³ it says that tetrahedra in a collection may be "solid 4-colored" so that no two glued face-to-face receive the same color.

Superhydrophobic Thin Films Fabricated By Reactive Layer-By-Layer Assembly Of Azlactone-Functionalized Polymers, Maren E. Buck, Sarina C. Schwartz, David M. Lynn

Chemistry: Faculty Publications

We report an approach to the fabrication of superhydrophobic thin films that is based on the "reactive" layer-by-layer assembly of azlactone-containing polymer multilayers. We demonstrate that films fabricated from alternating layers of the azlactone functionalized polymer poly(2-vinyl- 4,4-dimethylazlactone) (PVDMA) and poly(ethyleneimine) (PEI) exhibit micro- and nanoscale surface features that result in water contact angles in excess of 150°. Our results reveal that the formation of these surface features is (i) dependent upon film thickness (i.e., the number of layers of PEI and PVDMA deposited) and (ii) that it is influenced strongly by the presence (or absence) of cyclic azlactone-functionalized oligomers …

Reviewed Work(S): Baroque 1620–1800: Style In The Age Of Magnificence, John E. Moore

Art: Faculty Publications

No abstract provided.

Using Knowledge Building To Support Deep Learning, Collaboration And Innovation In Engineering Education, Glenn W. Ellis, Alan N. Rudnitsky, Mary A. Moriarty

Engineering: Faculty Publications

Knowledge building is a potentially transformative approach to engineering education. In knowledge building students participate in an interactive discourse in which they work together to broaden ideas, reform problems and share knowledge - the result being a deeper level of understanding and the collaborative production of new knowledge. In 2009 we conducted a knowledge building pilot study in the Picker Engineering Program at Smith College. In this study students worked together to formulate a question about the potential for a conscious machine and then engaged in an intensive knowledge building discourse. Assessment data showing the effectiveness of the approach and …

Frequency And Severity Approaches To Indexing Exposure To Trauma: The Critical Incident History Questionnaire For Police Officers, Daniel S. Weiss, Alain Brunet, Suzanne R. Best, Thomas J. Metzler, Akiva Liberman, Nnamdi Pole, Jeffrey A. Fagan, Charles R. Marmar

Psychology: Faculty Publications

The Critical Incident History Questionnaire indexes cumulative exposure to traumatic incidents in police by examining incident frequency and rated severity. In over 700 officers, event severity was negatively correlated (rs = -61) with frequency of exposure. Cumulative exposure indices that varied emphasis on frequency and severity-using both nomothetic and idiographic methods-all showed satisfactory psychometric properties and similar correlates. All indices were only modestly related to posttraumatic stress disorder (PTSD) symptoms. Ratings of incident severity were not influenced by whether officers had ever experienced the incident. Because no index summarizing cumulative exposure to trauma had superior validity, our findings suggest that …

Agreement Between Clinician And Patient Ratings Of Adaptive Functioning And Developmental History, Jared A. Defife, Rebecca Drill, Ora Nakash, Drew Westen

School for Social Work: Faculty Publications

Objective: Psychiatric researchers rely heavily on patient report data for clinical research. However, patient reports are prone to defensive and self-presentation biases. Recent research using practice networks has relied on clinician reports, and both forensic and personality disorder researchers have recently turned to quantified data from clinically expert observers as well. However, critics have raised legitimate concerns about the reliability and validity of data from clinician informants. The aim of this study was to assess the validity and diagnostic efficiency of clinician reports of their patients' adaptive functioning and developmental histories, using patient reports as the comparative standard traditionally used …

Normative Reflectance And Transmittance Measurements On Healthy Newborn And 1-Month-Old Infants, Gabrielle R. Merchant, Nicholas J. Horton, Susan E. Voss

Engineering: Faculty Publications

Objective:

Ear-canal-based wideband reflectance (WBR) measurements may provide objective measures to assess and monitor middle-ear status in young babies. This work presents WBR measurements of power reflectance and transmittance on populations of healthy newborn babies (3 to 5 days) and healthy 1-mo-old babies (28 to 34 days). Thus, this work determines how power reflectance and transmittance vary between newborn and 1-mo-old babies and characterizes the range of these measures in normal populations.

Design:

Power reflectance and transmittance were calculated from pressure measurements made in the ear canals of seven newborn (12 ears) and eleven 1-mo-old (19 ears) babies. Permutation tests, …

Campus Assessment Of Building Heating Energy Consumption-Informing The Climate Action Plan, E. Grover-Silva, D. A. Mckahn, D. Weisbord

Engineering: Faculty Publications

We present a methodology to assess the technical feasibility of building thermal energy reduction strategies from an architecturally diverse building stock that is not metered. While carbon emissions forecasting efforts are typically the domain of planning and policy, the process detailed here can inform institutional decision-making relative to investments in renewable energy, infrastructure, and offsets to further reduce carbon footprint. As a case study, we estimated the Smith College campus building thermal energy losses, an analysis which informed our Sustainability and Climate Action Plan [1]. Due to building specific physical constraints and planned renovations, different thermal envelope improvement scenarios were …

Personality And Politics: Introduction To The Special Issue, Lauren E. Duncan, Bill E. Peterson, Eileen L. Zurbriggen

Psychology: Faculty Publications

This special issue of Journal of Personality brings together 10 original articles addressing the intersection of personality and politics. Articles build on classic traditions in political psychology by presenting both idiographic and nomothetic work on the motivational, cognitive, ideological, attitudinal, and identity correlates of many different aspects of political behavior. This work is used to understand political activism and leadership as well as everyday political behavior. We hope this collection of articles will inspire our readers to explore new investigations in personality and political psychology.

Slider-Pinning Rigidity: A Maxwell-Laman-Type Theorem, Ileana Streinu, Louis Theran

Computer Science: Faculty Publications

We define and study slider-pinning rigidity, giving a complete combinatorial characterization. This is done via direction-slider networks, which are a generalization of Whiteley’s direction networks.

Sweeping Minimum Perimeter Enclosing Parallelograms: Optimal Crumb Cleanup, Yonit Bousany, Mary Leah Karker, Joseph O'Rourke, Leona Sparaco

Computer Science: Faculty Publications

We examine the problem of pushing all the points of a planar region into one point using parallel sweeps of an infinite line, minimizing the sum of the lengths of the sweep vectors. We characterize the optimal 2-sweeps of triangles, and provide a linear-time algorithm for convex polygons.

Testing Mechanisms Of Subduction Zone Segmentation And Seismogenesis With Slip Distributions From Recent Andean Earthquakes, John P. Loveless, M. E. Pritchard, K. Kukowski

Geosciences: Faculty Publications

A long-standing goal of subduction zone earthquake studies is to determine whether or not there are physical processes that control seismogenesis and the along-strike segmentation of the megathrust. Studies of individual earthquakes and global compilations of earthquakes find favorable comparison between coseismic interplate slip distributions and several different long-lived forearc characteristics, such as bathymetry, coastline morphology, crustal structure, and interplate frictional properties, but no single explanation seems to govern the location and slip distribution of all earthquakes. One possible reason for the lack of a unifying explanation is that the inferred earthquake parameters, most importantly the slip distribution, calculated in …

Interaction-Dependent Pcr: Identification Of Ligand-Target Pairs From Libraries Of Ligands And Libraries Of Targets In A Single Solution-Phase Experiment, Lynn M. Mcgregor, David J. Gorin, Christoph E. Dumelin, David R. Liu

Chemistry: Faculty Publications

Interaction-dependent PCR (IDPCR) is a solution-phase method to identify binding partners from combined libraries of small-molecule ligands and targets in a single experiment. Binding between DNA-linked targets and DNA-linked ligands induces formation of an extendable duplex. Extension links codes that identify the ligand and target into one selectively amplifiable DNA molecule. In a model selection, IDPCR resulted in the enrichment of DNA encoding all five known protein-ligand pairs out of 67 599 possible sequences.

Exploring Participant Perspectives On The Relationship Between Social Change Theater And Social Change Movements : A Project Based Upon An Investigation At The San Francisco Mime Troupe, Sins Invalid And The Outlook Community Theatre Project, San Francisco, California, Jesse Ehrensaft-Hawley

Theses, Dissertations, and Projects

This qualitative, exploratory study was designed to examine social change theater program participants' perspectives on the connection between their participation and their perceived capacity to create systemic social change. The research pursued the following questions: 1) How has participation in social change theatre affected the participants' sense of agency to create collective social change at the macro level; 2) What do participants perceive as their impact on systemic social change in relation to their participation in social change theater? 3) How do participants perceive the interaction of change at the level of the macro with change they may have experienced …

Therapist's Views Of How Hope Influences The Setting And Attainment Of Treatment Goals Among Clients With Posttraumatic Stress Disorder : A Qualitative Study : A Project Based Upon An Independent Investigation, Courtney Anne Jones

Theses, Dissertations, and Projects

The purpose of the current study was to determine the way that therapists view the role that hope plays in the treatment of clients with Posttraumatic Stress Disorder, specifically in regard to the treatment planning process and attainment of treatment goals. This exploratory qualitative study aims to contribute to previously existing literature about hope and its influence on treatment processes and focused on the areas of: (a) the role of hope in the therapeutic process, (b) hope and PTSD, (c) the assessment of hope, (d) fostering hope, (e) PTSD and treatment goals, and (f) hope, PTSD, and treatment goals. Ten …

Asian Americans And Cultural Values : Encountering And Overcoming Sociocultural Barriers To Community Mental Health Services : A Project Based Upon An Independent Investigation, William Lee

Theses, Dissertations, and Projects

This qualitative study explored the narrative experience of Asian American/Pacific Islanders (AA/PIs), who have received or are currently receiving community mental health services. This study was an attempt to illuminate their experience of encountering and overcoming socio-cultural barriers to these services. Historic underutilization of mental health services among AA/PI communities motivated the need to explore what cultural and/or institutional factors reduce barriers to services. Four AA/PIs, with an average length of 7.25 years in treatment, were recruited from a community mental health agency in San Francisco, CA. They participated in 45- minute to one hour semi-structured interviews discussing their experience …

An Exploratory Study Of The Life Experiences Of Gay, Lesbian And Bisexual People Who Were Raised In The U.S.A. Mennonite Church : A Project Based Upon An Independent Investigation, Adele Kathleen Liechty

Theses, Dissertations, and Projects

The purpose of this study is to explore the life experiences of persons who were raised in the U.S.A Mennonite Church and came to identify as Gay, Lesbian, or Bisexual. The research was a qualitative study with a sample of 10 self-identified GLB people, who were raised in the Mennonite Church. Through face-to-face interviews, participants were asked to reflect on their life experiences as it pertained to being raised Mennonite and identifying as GLB. They were asked specifically to think about the intersections of their Mennonite identity with their GLB identity development. The findings of this study highlight the complex …

Contemplative Practice, Internal Family Systems And Affect Regulation : An Exploratory Study : A Project Based Upon An Independent Investigation, Jessica Jeanne Prodis

Theses, Dissertations, and Projects

This exploratory study was undertaken to investigate the ways that contemplative practices across varied traditions may aid practitioners in the development of tools for emotional containment and regulation. The Internal Family Systems (IFS) model of psychotherapy (Schwartz, 1995) was used as a theoretical framework for this study. Findings were compared to the ways that affect regulation and containment are conceptualized within the IFS model. Eleven subjects who identified as utilizing contemplative practices from various traditions participated in this study. Interview questions were designed to explore the ways that engagement in a daily contemplative practice for five or more years had …

An Examination Of The Relationship Between Self-Compassion And Burnout In Practicing Psychotherapists : A Project Based Upon An Independent Investigation, Jennifer Ann Thurlow

Theses, Dissertations, and Projects

Burnout is particularly a problem among people whose work involves responding to human suffering; therefore, without adequate personal resources to draw from, psychotherapists are especially at risk. Self-compassion is a powerful coping skill, thus therapists may be protected from burnout through the practice. The purpose of this study was to examine how self-compassion is related to burnout in practicing psychotherapists. It was hypothesized that higher total self-compassion scores would be associated with lower scores on the burnout subscales of emotional exhaustion and depersonalization and that higher scores of total self-compassion would be associated with higher scores on the burnout subscale …

Smoothness Of Lipschitz Minimal Intrinsic Graphs In Heisenberg Groups ℍN, N > 1, Luca Capogna, Giovanna Citti, Maria Manfredini

Mathematics Sciences: Faculty Publications

We prove that Lipschitz intrinsic graphs in the Heisenberg groups ℍn, with n > 1, which are vanishing viscosity solutions of the minimal surface equation, are smooth and satisfy the PDE in a strong sense.

Genome Dynamics Are Influenced By Food Source In Allogromia Laticollaris Strain Csh (Foraminifera), Laura Wegener Parfrey, Laura A. Katz

Biological Sciences: Faculty Publications

Across the eukaryotic tree of life, genomes vary within populations and within individuals during their life cycle. Understanding intraspecific genome variation in diverse eukaryotes is key to elucidating the factors that underlie this variation. Here, we characterize genome dynamics during the life cycle of Allogromia laticollaris strain CSH, a member of the Foraminifera, using fluorescence microscopy and reveal extensive variation in nuclear size and DNA content. Both nuclear size and DNA content are tightly correlated across a 700-fold range in cell volume. In contrast to models in yeast where nuclear size is determined solely by cell size, the relationship in …

Neural Activity Patterns In Response To Interspecific And Intraspecific Variation In Mating Calls In The Túngara Frog, Mukta Chakraborty, Lisa A. Mangiamele, Sabrina S. Burmeister

Biological Sciences: Faculty Publications

Background: During mate choice, individuals must classify potential mates according to species identity and relative attractiveness. In many species, females do so by evaluating variation in the signals produced by males. Male túngara frogs (Physalaemus pustulosus) can produce single note calls (whines) and multi-note calls (whine-chucks). While the whine alone is sufficient for species recognition, females greatly prefer the whine-chuck when given a choice. Methodology/Principal Findings: To better understand how the brain responds to variation in male mating signals, we mapped neural activity patterns evoked by interspecific and intraspecific variation in mating calls in túngara frogs by measuring expression of …

Filtering Of Visual Information In The Tectum By An Identified Neural Circuit, Filippo Del Bene, Claire Wyart, Estuardo Robles, Amanda Tran, Loren Looger, Ethan K. Scott, Ehud Y. Isacoff, Herwig Baier

Neuroscience: Faculty Publications

The optic tectum of zebrafish is involved in behavioral responses that require the detection of small objects. The superficial layers of the tectal neuropil receive input from retinal axons, while its deeper layers convey the processed information to premotor areas. Imaging with a genetically encoded calcium indicator revealed that the deep layers, as well as the dendrites of single tectal neurons, are preferentially activated by small visual stimuli. This spatial filtering relies on GABAergic interneurons (using the neurotransmitter γ-aminobutyric acid) that are located in the superficial input layer and respond only to large visual stimuli. Photo-ablation of these cells with …

Flat Zipper-Unfolding Pairs For Platonic Solids, Joseph O'Rourke

Computer Science: Faculty Publications

We show that four of the five Platonic solids' surfaces may be cut open with a Hamiltonian path along edges and unfolded to a polygonal net each of which can "zipper-refold" to a flat doubly covered parallelogram, forming a rather compact representation of the surface. Thus these regular polyhedra have particular flat "zipper pairs." No such zipper pair exists for a dodecahedron, whose Hamiltonian unfoldings are "zip-rigid." This report is primarily an inventory of the possibilities, and raises more questions than it answers.

Curvedland: An Applet For Illustrating Curved Geometry Without Embedding, Gary Felder, Stephanie Erickson

Physics: Faculty Publications

We have written a Java applet to illustrate the meaning of curved geometry. The applet provides a mapping interface similar to MapQuest or Google Maps; features include the ability to navigate through a space and place permanent point objects and/or shapes at arbitrary positions. The underlying two-dimensional space has a constant, positive curvature, which causes the apparent paths and shapes of the objects in the map to appear distorted in ways that change as you view them from different relative angles and distances.

Kahn Chronicle: Fall 2010, Smith College, Kahn Liberal Arts Institute

Kahn Chronicle

Table of Contents:

Marking Time: Smith's Newest Time Capsule
Information Sessions: Renaissances & Evil
2010-2011 Student Fellowships
Short-term Project Fellowship Opportunities
Neilson-Kahn Seminar
News Briefs
Tes Slominski: Mellon/ ACLS Fellow
Wellness & Disease Project Final Report
Telling Time Project Final Report
A Note from the Director

A Controllable Membrane-Type Humidifier For Fuel Cell Applications-Part I: Operation, Modeling And Experimental Validation, Denise A. Mckay, Anna G. Stefanopoulou, Jeffrey Cook

Engineering: Faculty Publications

For temperature and humidity control of proton exchange membrane fuel cell (PEMFC) reactants, a membrane based external humidification system was designed and constructed. Here we develop and validate a physics based, low-order, control-oriented model of the external humidification system dynamics based on first principles. This model structure enables the application of feedback control for thermal and humidity management of the fuel cell reactants. The humidification strategy posed here deviates from standard internal humidifiers that are relatively compact and cheap but prohibit active humidity regulation and couple reactant humidity requirements to the PEMFC cooling demands. Additionally, in developing our model, we …

Flattening Single-Vertex Origami: The Non-Expansive Case, Gaiane Panina, Ileana Streinu

Computer Science: Faculty Publications

A single-vertex origami is a piece of paper with straight-line rays called creases emanating from a fold vertex placed in its interior or on its boundary. The Single-Vertex Origami Flattening problem asks whether it is always possible to reconfigure the creased paper from any configuration compatible with the metric, to a flat, non-overlapping position, in such a way that the paper is not torn, stretched and, for rigid origami, not bent anywhere except along the given creases. Streinu and Whiteley showed how to reduce the problem to the carpenter's rule problem for spherical polygons. Using spherical expansive motions, they solved …

Broadly Sampled Multigene Analyses Yield A Well-Resolved Eukaryotic Tree Of Life, Laura Wegener Parfrey, Jessica Grant, Yonas I. Tekle, Erica Lasek-Nesselquist, Hilary G. Morrison, Mitchell L. Sogin, David J. Patterson, Laura A. Katz

Biological Sciences: Faculty Publications

An accurate reconstruction of the eukaryotic tree of life is essential to identify the innovations underlying the diversity of microbial and macroscopic (e.g., plants and animals) eukaryotes. Previous work has divided eukaryotic diversity into a small number of high-level "supergroups," many of which receive strong support in phylogenomic analyses. However, the abundance of data in phylogenomic analyses can lead to highly supported but incorrect relationships due to systematic phylogenetic error. Furthermore, the paucity of major eukaryotic lineages (19 or fewer) included in these genomic studies may exaggerate systematic error and reduce power to evaluate hypotheses. Here, we use a taxon-rich …

Essential Genes For Astroglial Development And Axon Pathfinding During Zebrafish Embryogenesis, Michael J.F. Barresi, Sean Burton, Kristina Dipietrantonio, Adam Amsterdam, Nancy Hopkins, Rolf O. Karlstrom

Biological Sciences: Faculty Publications

The formation of the central nervous system depends on the coordinated development of neural and glial cell types that arise from a common precursor. Using an existing group of zebrafish mutants generated by viral insertion, we performed a "shelf-screen" to identify genes necessary for astroglial development and axon scaffold formation. We screened 274 of 315 viral insertion lines using antibodies that label axons (anti-Acetylated Tubulin) and astroglia (anti-Gfap) and identified 25 mutants with defects in gliogenesis, glial patterning, neurogenesis, and axon guidance. We also identified a novel class of mutants affecting radial glial cell numbers. Defects in astroglial patterning were …