Optical and resonant X-ray diffraction investigations of molecular ordering in chiral smectic liquid crystals

Cady, Andrew Nickolas University of Minnesota 2003 해외박사(DDOD)

The research described in this thesis has been directed at characterizing and understanding molecular ordering in chiral smectic liquid crystals. The chiral smectic variant phases have been studied extensively in the last decade due to their promise in creating the next generation of high-speed optical switching devices. In addition, with many phases being exhibited within a small temperature window (<30K), chiral liquid crystals are excellent systems in which to study molecular interactions on both a theoretical and experimental level. In the research described, two unique experimental probes have been utilized: differential optical reflectivity (DOR) and resonant polarized x-ray diffraction (RPXRD). Using RPXRD, we have directly determined the molecular arrangement within a 4-layer biaxial repeat unit in the smectic-C*_F12 (Sm-C*_F12) phase. In the DOR experiment, we have dramatically refined the apparatus and the data modelling techniques in order to study the Sm-C*_α phase. We demonstrate how the molecules in this layered phase form an incommensurate nanoscale helical pitch (INHP). We describe an optical method to measure the size of the INHP, which can be as small as 10nm, using the smectic layer spacing as a benchmark. Through both DOR and RPXRD experiments, we have identified two dramatically different temperature evolutions of this structure in consecutive members of two homologous series. Our data suggest a possible continuous evolution of this pitch from the Sm-C*_α to the Sm-C* phase in some compounds. In addition, a phenomenological model that describes these results also predicts the existence of a new form of the Sm-C*_α phase that has been identified using DOR.

Nurture Trumps Nature: Genetics, the Environment, and Parenting and Their Effect on Child Food Intake and Childhood Obesity

Cady, Matthew ProQuest Dissertations & Theses The Pennsylvania S 2019 해외박사(DDOD)

The recent rise in obesity rates has been largely the result of drastic changes to the environment that affect food consumption. Specifically, decreased access to fresh, healthy food and an overabundance of cheap, processed, energy-dense foods. Genetics plays a large role in determining food consumption, mainly through appetite and it is likely that certain individuals may be more genetically prone to increase food intake in response to environmental cues. Lastly, parents play an important role in the determination child diet by way of modelling via their own and feeding styles and practices.This dissertation adds three separate studies to the literature regarding factors relating to child diet and obesity development. The first identifies dietary patterns in children using cluster analysis of food subgroups and finds children with a healthy dietary pattern have a significantly lower BMI and healthier lifestyle factors including reduced screen time and increased sleep duration. Study two utilizes an adoption study design with dietary intake measures from both children adopted at birth and their birth and adoptive parents. Measures of child diet were significantly correlated with adoptive and not birth parent diet showing that previously-found associations between parent and child diet are largely the result of environmental and not genetic factors. The third study investigates the effects of parental feeding practices, namely restriction and pressure to eat, on child dietary intake and the effect that child sex may play in moderating this relationship. Although there were no significant interaction effects for child sex, when correlations were performed separately, potential sex differences in the way children may respond to parent feeding practices are revealed.These three studies, taken together, preceded by a thorough review of the literature, inform of the relative importance of environmental and genetic factors as well as the pivotal role of parents in shaping child diet. Understanding how and the extent to which each of these factors affect child dietary intake is of vital importance. In order to reduce childhood obesity prevalence, environmental reforms aimed at increasing access to healthy food and improving parent diet and feeding practices are imperative.

Design, tolerancing, and experimental verification of occulters for finding extrasolar planets

Cady, Eric Princeton University 2010 해외박사(DDOD)

A key science goal in the exoplanet community is the detection and characterization of planets with similar properties to Earth. However, this is a difficult task, as planets are much fainter than their host stars and are often at small angular separations. In particular, Earth-like planets---that is, rocky planets in habitable zones---are estimated to be ten billion times dimmer than the stars they orbit, and are located at angular separations on the order of a hundred milliarcseconds around nearby stars. One method of finding these Earth-size planets is by using an occulter, a spacecraft with a shaped edge flown in formation with a telescope. The size of the occulter and its location are chosen so that the occulter suppresses the light from the star by ten orders of magnitude or more over a particular wavelength band, while leaving the planet light unaffected. Most designs have the occulter tens of meters in diameter, and separated from the telescope by tens of thousands of kilometers, which gives the occulter an angular size on the order of a hundred milliarcseconds. In this thesis, I discuss our methods of designing occulters using optimization methods; of estimating their tolerances to misalignments, manufacturing errors, and transient deformations using analytic techniques; and some of the modifications that can be made to their shapes while maintaining their properties of high light suppression. I will also discuss some particular realizations of occulter system in THEIA and O3, two mission concepts which use occulters to find Earth-like planets, and present the design of an experiment to verify the performance of occulters, along with data demonstrating mask performance and tolerancing.

College student spiritual development: A narrative study of peer conversation

Cady, Deborah M Boston College 2006 해외박사(DDOD)

College student peer groups have long been known to have a great impact on student learning and development. Recent research (Astin & Astin, 2004) suggests that the peer group is the primary conduit for the spiritual conversation among college students. Students are asking meaning-of-life questions with their peers in order to understand their own sense of identity and the world. This study examined spiritual development by exploring the impact of the peer group on the spiritual conversation. This narrative study described how four senior friendship groups from two different small liberal arts residential institutions made meaning of their spiritual development within peer conversation. The methodology utilized focus group interviews, individual interviews and document analysis of institutional mission statements as the tools in gathering data. Data were then analyzed through thematic coding within the framework of narrative analysis. Several themes emerged as central to the spiritual development narrative in the peer conversation including student views of spirituality, conversations of meaning, conversation catalysts, and the conversationalists. Students viewed spirituality as a person's connection to wholeness and divineness as well as both an innately personal yet often communal quest. As students experienced spirituality in community through peer conversations, students asked meaning-of-life questions in order to understand their identity, their relationships with others, the world and faith. Experiences in the classroom, in their personal lives and in the world initiated peer inquiry of each other and with wise mentors. These findings suggested student use of spirituality as a tool for identity development, for conversations regarding religious differences, and for coping with life's curveballs. In addition, this study found that spiritual conversations had a niche on the college campus primarily in religious organizations, classroom discussions and close friendship groups. Finally, student resistance to conflict acted as an inhibitor to conversations of religious difference. From these findings, several recommendations for student affairs educators were suggested to enhance practices on campus that empower spiritual conversations and development.

Modeling photosystem II using manganese, a study of photochemistry and electrochemistry

Cady, Clyde William Yale University 2008 해외박사(DDOD)

Green plants and cyanobacteria possess the four manganese single calcium cluster necessary to oxidize water to O2. The photosynthetic process by which four flashes of light and two water molecules are transformed into O2 and a proton gradient is one of the most interesting and challenging in nature. We, along with many others, work to better understand the first step in photosynthesis by mimicking it with small molecules. We attempt to understand the mechanism for oxidizing water by single electron steps through the use of electrochemistry. This study has demonstrated the necessity of proton coupled electron transfer (PCET) in the mechanism of water oxidation as well as shown how the coordination of simple ligands can have a great effect upon the reduction potential of high valent intermediates. The electrochemical studies shown here will hopefully lead to the first catalytic oxidation of water with a manganese catalyst using one electron oxidants. In this thesis, we also detail the development of TiO2 based photochemistry capable of oxidizing manganese complexes. Manganese model chemistry is very close to oxidizing water through discrete one electron steps, but to truly mimic the natural system, we must carry out oxidation with light. The new photochemical system shown in this thesis details the mechanism involved in oxidizing a manganese complex immobilized on a semiconductor surface using visible light.

"Al is for to selle": Money, language and gender in the "Canterbury Tales" (Geoffrey Chaucer)

Cady, Diane Marie Cornell University 2001 해외박사(DDOD)

This dissertation pursues the intersections between money, language and gender in the Middle Ages in general and in the Canterbury Tales in particular. I argue that the ubiquity with which these signifying systems intersect indicates a relationship that is more than merely metaphorical. These three registers are what Anne McClintock has called “articulated categories”—categories that come into being by and through their relation to one another. In this study I explore these relations in two areas in particular: medieval rhetoric and arguments about the “naturalness” of social order. Medieval poets and rhetoricians depicted writing as an activity analogous to the selling of goods. Texts are commodities that a writer “sells” to his reader through the skillful use of figurative language. In addition, they are often presented as “feminine” <italic>corpora</italic> to be written, read and in the words of the Wife of Bath, “glossed” by men. As a consequence, descriptions of the opening and displaying of these textual commodities often contain a highly sexual charge. Gender dynamics also play a role in notions of what makes a story valuable, in both an aesthetic and an economic sense. Valuable texts are often described as both expensive commodities and as sexually pure women, whereas worthless texts are depicted as “used” commodities and as sexually “used” women. Chaucer explores these and other aspects of the poetic marketplace in both the <italic>Wife of Bath's Prologue</italic> and <italic>Tale</italic> and in the <italic>Man of Law's Tale</italic>. The second issue I examine is how medieval discussions of money, language and gender share a similar tension: a realization that these signifying systems are conventional and yet a nostalgia for “natural” origins. I argue that this seeming contradiction belies an anxiety that if these systems are conventional (and thus subject to change) than society itself is built on unstable ground. It is for this reason that discussions of language, gender and money extend so frequently into more general discussions about law and order. Chaucer's interest in issues of social disorder and their relationship to “nature” are most explicitly articulated in the <italic>Pardoner's Tale</italic>. The Pardoner is avaricious, sexually ambiguous and linguistically perverse. Thus we see in the Pardoner the nexus of money, gender and language that is the central focus of this study. However, Chaucer does not use these “perversions” as a way to argue for the “unnaturalness” of his narrator, but rather as a way to question the use of “nature” as a means of consolidating society's ordering agenda.

"Southern" California: White southern migrants in Greater Los Angeles, 1920--1930

Cady, Daniel Jay The Claremont Graduate University 2005 해외박사(DDOD)

This dissertation examines the impact and significance of white southern migration to southern California in the 1920s. Between World War I and the Great Depression, white southerners established a migratory pattern that funneled hundreds of thousands of dislocated working-class men and women into the lower half of the Golden State. Unwanted by some, despised by a few, but accepted by the majority, these migrants arrived on the outskirts of the West's largest metropolis and quietly transformed "Iowa by the Sea," into a interregionally diverse and slightly chaotic land of sprawling industrial suburbs pushing against receding fields and pastures. Through this dissertation I chart the flow of southern migration to the West, reveal the presence of southerners prior to the Okies, and argue that during the 1920s Los Angelenos' generally positive attitudes towards white southerners reflected a greater positive assessment of white southern culture during a period of national reconciliation. Before Okie became pejorative, white southerners bypassed the San Joaquin Valley to seek work in southern California's oil fields, with hardly a disparaging word. Though Los Angeles's business elite feared the southern presence, and black Angelenos battled against the importation of white southern culture, many---in a period of national reunion---embraced the ideological song of the South. From the southern Reconstruction narrative of Birth of a Nation, to the religious and social conservatism of Los Angeles's Southern Methodist Church and vibrant Ku Klux Klan, southern ideas found a receptive audience in the City of Angles. This dissertation explores the lives of those who transmitted those ideas in a period before the sons and daughters of the South became Okies and Arkies.

Discursive Constructions: Space and Time in Northern Italy in the Late Fourth Century

Cady, Alyssa M Princeton University ProQuest Dissertations & Thes 2022 해외박사(DDOD)

Late Antique scholars have become increasingly interested in questions of regionality, time and landscape, as well as the intersection between oral and visual media. A fruitful angle from which to examine these topics proves to be the cult of saints in northern Italy in the late fourth century, due to the conception of saint as exemplar and to its manifestation in physical and discursive spaces. My dissertation compares three figures who provide different viewpoints on these issues, namely: Zeno of Verona, Ambrose of Milan, and the poet Prudentius. It examines lesser-known evidence, such as Prudentius’ Tituli Historiarum, and provides the first English translations of four sermons of Zeno as well as Ambrose’s Disticha. We begin with Zeno, whose tenure coincides with the earliest sermons in Latin, as well as the earliest martyr veneration and church-building in Verona. His Tractatus illuminate a tightrope upon which this bishop balanced pious intervention against the stubborn autonomy of his congregants. Ambrose, meanwhile, enjoyed far greater resources than his Veronese predecessor, and compares contemporary substitutes to historical exemplars whom he integrated into nascent ecclesiastical institutions. In Prudentius we see the rise of the elite Christian poet, whose concerns differed from episcopal programs of authoritative expansion. He periodizes history through the lens of triumph and decline, explaining contemporary practice through exemplars. In these figures, we see a generational and professional divide in their use of space and history as ideological canvases upon which to layer ideals of Christian ethics.

The boundaries of sisterhood: Race, class, gender, and participation in Michigan's welfare rights movement and response to welfare policy, 1964--1972

Edmonds-Cady, Cynthia Michigan State University 2006 해외박사(DDOD)

This historical, qualitative study used the combined methods of oral history and document analysis to examine how race, class, and gender intersected in women's participation in the welfare rights movement and their responses to changes in welfare policy during the period between 1964 and 1972. A multidimensional feminist standpoint approach (Naples, 2003) and an intersectional approach were used to inform the conceptual framework for this study, and the literature on women's historical participation in social movements, the development and dismantling of the National Welfare Rights Organization, and historical changes in welfare policy during the Johnson and Nixon administrations were also examined. This research focused on Detroit and Southeast Michigan, and examined how women in the welfare rights movement crossed and/or maintained boundaries of race and class while acting from a similar gender perspective. Interviews were conducted with 13 participants in the welfare rights movement in the Detroit, Michigan area and documents from various archival sources were analyzed. Primary sources, documents created by movement participants, were examined. Results of this study indicate that a shared standpoint of "woman" was particularly evident in non-recipient "friends of welfare rights" initial motivation to join the movement, and a strong poverty-class standpoint was emphasized in recipient members' participation. Maternalism was a significant mobilization feature for the friends of welfare rights; however, a practical maternalism emerged within the recipients' motivation and involvement in the welfare rights movement. Documents that responded to changes in welfare policy most frequently emphasized gender, particularly motherhood and the right to financial support. Overall, race and class based differences were emphasized most in decision making, tactics, and control within the movement. Within the documents, race was used in a more divisive way in responding to welfare policy changes, calling up images of slavery and oppression, and class was used ambivalently by including "working families" and "working mothers" in calls to fight against policies that would harm poor women on welfare. Where boundaries of race and class were able to be crossed within this sample, it was when non-recipients engaged in the same activities as recipients, but encouraged control and leadership to be maintained by recipients. These results indicate that similarities in gender or motherhood status were helpful in motivating some individuals to initially form linkages across difference, but connections were complicated based on differences in the ways that class and race intersected gender. This dissertation is an interdisciplinary study that fills gaps in the literature within the fields of social work and community practice, social work advocacy, women's history, women's studies, and sociology.

Ecology and impacts of coyotes (canis latrans) in the southeastern united states

Etheredge, Cady Rose Clemson University 2013 해외박사(DDOD)

Recent coyote (Canis latrans) colonization of the southeastern United States has prompted speculation on the top-down effects of a new top predator on systems which have gone without a strong predator presence since the extirpation of the red wolf (Canis rufus). This dissertation reports on the results of a series of investigations of the potential impact of coyotes on raccoons (Procyon lotor) and other management issues related to coyotes in the Southeast. Chapters 1-3 present indirect field tests of the Mesopredator Release Hypothesis. Chapter 4 presents an overview of the current knowledge of the ecology and potential impacts of coyotes in the Southeast.