Geography and Genetics of Ecological Speciation in Pea Aphids

During ecological speciation, divergent natural selection drives evolution of ecological specialization and genetic differentiation of populations on alternate environments. Populations diverging onto the same alternate environments may be geographically widespread, so that divergence may occur at an array of locations simultaneously. Spatial variation in the process of divergence may produce a pattern of differences in divergence among locations called the Geographic Mosaic of Divergence. Diverging populations may vary in their degree of genetic differentiation and ecological specialization among locations. My dissertation examines the pattern and evolutionary processes of divergence in pea aphids (Acyrthosiphon pisum) on alfalfa (Medicago sativa) and clover (Trifolium pretense). In Chapter One, I examined differences among North American aphid populations in genetic differentiation at nuclear, sequence-based markers and in ecological specialization, measured as aphid fecundity on each host plant. In the East, aphids showed high host-plant associated ecological specialization and high genetic differentiation. In the West, aphids from clover were genetically indistinguishable from aphids on alfalfa, and aphids from clover were less specialized. Thus, the pattern of divergence differed among locations, suggesting a Geographic Mosaic of Divergence. In Chapter Two, I examined genomic heterogeneity in divergence in aphids on alfalfa and clover across North America using amplified fragment length polymorphisms (AFLPs). The degree of genetic differentiation varied greatly among markers, suggesting that divergent natural selection drives aphid divergence in all geographic locations. Three of the same genetic markers were identified as evolving under divergent selection in the eastern and western regions, and additional divergent markers were identified in the East. In Chapter Three, I investigated population structure of aphids in North America, France, and Sweden using AFLPs. Aphids on the same host plant were genetically similar across many parts of their range, so the evolution of host plant specialization does not appear to have occurred independently in every location. While aphids on alfalfa and clover were genetically differentiated in most locations, aphids from alfalfa and clover were genetically similar in both western North America and Sweden. High gene flow from alfalfa onto clover may constrain divergence in these locations.

Specializing pedestrian maps to address the needs of people using wheelchairs: a case study in community-sustainable information systems

Gemstone Team FASTR (Finding Alternative Specialized Travel Routes)

Selected Works from Character Pieces in the 19th - Early 20th Centuries

During the Romantic Era, the character piece flourished and became one of the most important genres. Even though character pieces existed as early as the eighteenth century, it was not until the nineteenth century that Romantic Era literary figures discovered that music was as powerful as any other artistic medium in expressing unspeakable emotions. The character piece allowed composers to express a definite mood, a programmatic idea, or a pictorial association. Character pieces often have titles that suggest briehess or casualness, such as a Beethoven Bagatelle, a Schubert Impromptu or Moment musicaux. Others have expressive programmatic titles, such as Schumann's Kreisleriana and Liszt's Apres une lecture de Dante. Ths dissertation was based on selected works from the nineteenth century and early-twentieth century in order to demonstrate the great variety of musical thought and stylistic development. I have examined composers from different countries and of different nationalities to establish what and how they contributed to the remarkable diversity in this genre. The selected works allowed for very personal programs. These concerts, in addition to being good combinations of pieces, are representative of the genre. The first program consisted of Chopin's Preludes, Op. 28; three pieces from Debussy7s Images Books I and 11; and Liszt7s Apres une lecture de Dante. The second program included seven of Beethoven's Bagatelles, Op. 33; Schumann's Kinderscenen, Op. 15; Poulenc's Mouvements perpetuels and Intermezzo in A-jlat Major; Faure7s Nocturne in B Major, Op. 33, No. 2 and Impromptu No. 2 in F Minor; three of Mompou's Canciones y Danzas; four of Villa-Lobos Prole do bebe Suite No. 1; and Albkniz's Navarra. The third and final program comprised four selections from Rachrnaninoff s Moment musicaux, Op. 16; five pieces from Grieg's Lyric Pieces; and Arensky7s Suite No. 1 for Two Pianos and Suite No. 2 for Two Pianos. I wanted to bring out nuances specific to the individual composers and show how their character pieces helped in shaping the Romantic Era. Even in the twenty-first century, an era of highly specialized musical tastes, the popularity and accessibility of character pieces stand out.

Making it in the Modern Job Market: A Study of Communication among the Deaf and Hard of Hearing Population

Gemstone Team AUDIO (Assessing and Understanding Deaf Individuals' Occupations)

Developing Quantitative Methodologies for the Digital Humanities: A Case Study of 20th Century American Commentary on Russian Literature

Using scientific methods in the humanities is at the forefront of objective literary analysis. However, processing big data is particularly complex when the subject matter is qualitative rather than numerical. Large volumes of text require specialized tools to produce quantifiable data from ideas and sentiments. Our team researched the extent to which tools such as Weka and MALLET can test hypotheses about qualitative information. We examined the claim that literary commentary exists within political environments and used US periodical articles concerning Russian literature in the early twentieth century as a case study. These tools generated useful quantitative data that allowed us to run stepwise binary logistic regressions. These statistical tests allowed for time series experiments using sea change and emergency models of history, as well as classification experiments with regard to author characteristics, social issues, and sentiment expressed. Both types of experiments supported our claim with varying degrees, but more importantly served as a definitive demonstration that digitally enhanced quantitative forms of analysis can apply to qualitative data. Our findings set the foundation for further experiments in the emerging field of digital humanities.