CU Dissertations
Pages
-
- Seneca and the Stoic Appropriation of Tragic Exempla
- This study claims that a shared concern among the philosophical and dramatic works of Seneca the Younger (4 BC – AD 65) is the inadequacy of exempla to teach virtue. As the only non-fragmentary Latin tragedies to survive from antiquity and the only extant dramas written by a Stoic philosopher, Seneca’s dramas may initially strike the reader as anomalous. Yet, Stoic sources suggest a tradition of appropriating tragic figures as exempla at least from the time of Chrysippus. Seneca’s dramas, however, do not put straightforward exempla of virtue or vice on stage, as has often been claimed, nor do they teach Stoicism. Instead, Seneca engages with the Stoic tradition by recasting characters who were established as exempla in the literary record and exposing their inconsistency and inadequacy to model perfect virtue.The first chapter explores Seneca’s steady interest in exemplarity and the stage across his corpus, focusing on Ad Marciam, the Epistulae morales, and the tragedies. Expanding upon Roller’s (2018, ch. 8) analysis of the critique of exemplarity that Seneca articulates in his prose works, I demonstrate that Seneca believed only an observably consistent role model could teach perfect virtue; I call this person the “extended exemplum.” I show that Seneca maintains a consistent theory of exemplarity throughout his Epistulae and that he regularly uses words in specific semantic categories to introduce or discuss exempla; I call this the “language of exemplarity.” The second and third chapters present two case studies: Hercules and Polyxena, each of whom was deployed by ancient Greek and Roman authors to exemplify virtues important in Stoicism: interior freedom and noble death. I begin each chapter with a chronological outline of these sources. Euripides and Philo of Alexandria figure prominently in the evidence for both characters. The Stoic tradition of appropriating Hercules as an exemplum of virtue is well documented and acknowledged by Seneca himself (Const. 2.1). Limited evidence suggests that Polyxena was of special interest to Stoic philosophers; she was at least recognizable as a model of virtuous death in Roman sources by Seneca’s day. Seneca engages with these traditions when he foregrounds interior freedom, virtuous death, and exemplarity as themes in the Hercules furens and in the Troades. In different ways, the characters or internal audience in each play establish an expectation that Hercules and Polyxena will model interior freedom. Yet, by the end of their respective tragedies, both figures prove to be inconsistent in virtue, according to the criteria found in Seneca’s philosophical works. They illustrate his critique of exemplarity and cannot serve as extended exempla, despite the opportunity for extended observation afforded by drama. A similar trajectory can be discerned for Hercules of the Hercules Oetaeus, whose author was probably an imitator of Seneca, as well as for Astyanax, who serves as a doublet for Polyxena in the Troades. My close reading of Seneca's tragedies alongside his philosophical works demonstrates that one major purpose of the dramas is to illustrate the inadequacy of typical rhetorical exempla to teach virtue. , Classical studies, Classical literature, Philosophy, Exempla, Hercules, Seneca, Stoicism, Tragedy, Troades, Greek and Latin, Degree Awarded: Ph.D. Greek and Latin. The Catholic University of America
-
- Senior Women's Body Image Perceptions and Successful Aging Beliefs
- Senior Women’s Body Image Perceptions and Successful Aging BeliefsKathleen M. Brandenburg, Ph. D.Director: Janet S. Selway D. N. Sc.Women age 65 and over accounted for over half (56%) of the U.S. population in 2014 (FederalInteragency Forum on Aging Research, (FIFARS), 2016). Only 19 % of U.S. adult womenfollow the 2018 Physical Activity Guidelines for Americans (PAGA) recommendations (U.S.Department of Health and Human Services [HHS], 2018). Failure to meet recommended levelsof aerobic physical activity is associated with 10% of all premature mortality and anticipatedannual health care costs of $117 billion (HHS, 2018). The purpose of this study was to explorethe lived experience of body image perception and successful aging beliefs of senior womenwho exercise a minimum of the recommended 150 minutes per week. The human becomingtheory of Rosemarie Parse (1992) and the phenomenological methods of Merleau-Ponty (1945)guided this study. Twelve senior women aged 65 and above, who resided in North Myrtle Beach,SC, and engaged in recommended levels of exercise participated in the study.Using semi-structured recorded interviews, study participants expressed feelings about theirbody image and what they believe about successful aging. Thematic analysis identified anoverarching theme of continued well-being and five essential themes: (a) perception andpositivity regarding body image; (b) exercise and commitment; (c) intersection of activities ofdaily living management and community, (d) self-contentment and positivity regarding themeaning of successful aging and physical fitness, and (e) reassurances and concerns insuccessful aging. The senior women were found to desire continued well-being. To achievecontinued well-being, the senior women exercised at a high level, understood the importance ofdiet, fluids, and rest, and gained the added benefit of increased socialization. The findings of thisstudy provided insight regarding the meaning and experiences of successful aging, body imageand exercise in the everyday lives of senior women. An in depth understanding of the livedexperience of aging senior women known to participate in regular exercise will inform futurestudies and interventions regarding the impact of exercise on senior women’s health. Futureresearch should explore senior women’s health and well-being to gain further insight into thisgrowing population and aid the development of supportive interventions and policies., Aging, Nursing, Degree Awarded: Ph.D. Nursing. The Catholic University of America
-
- The Senses and Sensory Metaphors in Augustine's Early Works
- The vast corpus of Augustine of Hippo is full of references to the five senses, and full of sensory metaphors, but little scholarly attention has been given to Augustine’s understanding of the physics of sense-perception, or to his definition and use of sensory metaphors. This dissertation aims, in part, to fill both gaps by examining Augustine’s early writings, from the Cassiciacum Dialogues to the Confessions, to ascertain first his views on the physiological aspects of sense-perception, and to explore his use of sensory metaphors. The first part of this project is a necessary precursor to the second part, as Augustine’s sensory metaphors are based on the analogy of the bodily senses to certain activities or faculties of the soul. In his early works, Augustine presents a consistent picture of the senses, their hierarchy, and their association with the Empedoclean four elements (fire, air, water, and earth). In keeping with his broad but nuanced definition of metaphor, Augustine uses sensory metaphors in ways that reflect his larger philosophical and theological preoccupations. Throughout his early works, and especially in the Confessions, Augustine produces the metaphoric pattern of a voice that leads to vision, which reflects his theme of faith seeking understanding. In the end, metaphor, as Augustine defined and deployed it, is not a mere literary device, but a way of seeing the world., Classical studies, Classical literature, Ancient languages, Metaphor, Philosophy, Rhetoric, Senses, Theology, Greek and Latin, Degree Awarded: Ph.D. Greek and Latin. The Catholic University of America
-
- Septic Shock and Vasopressor Therapy: The Impact of Excessive Mean Arterial Pressure Values
- Septic Shock and Vasopressor Therapy: The Impact of Excessive Mean Arterial Pressure Values Barbara Clark Mims, PhD Director: Nalini Jairath, PhD, MSc.N., RN Abstract Septic shock consists of circulatory failure secondary to infection. During septic shock, mediator-induced vasodilation causes hypotension, requiring vasopressor therapy to restore vascular tone and hemodynamic stability. While life-sustaining, vasopressors may cause harm, especially when delivered at higher doses. Regulatory standards require providers’ orders to include a maximum dose and a titration target, which usually consists of a mean arterial pressure (MAP) value. However, a maximum MAP value is neither required nor routinely ordered. This leaves the nurse with discretion regarding the dose delivered and MAP value maintained. For almost two decades, a MAP target value of ≥ 65mmHg has prevailed. However, actual MAP values often substantially exceed ordered target values. Controversy exists regarding the ideal MAP target value, but achieving higher MAP values clearly requires higher vasopressor doses. Problem. During vasopressor therapy for patients in septic shock, actual MAP values often exceed the recommended titration target of 65 mmHg and may contribute to adverse outcomes. Research Method. This retrospective, correlational, longitudinal study used the Medical Information Mart for Critical Care (MIMIC-III) database to obtain a sample of 188 critically ill adults diagnosed with septic shock. Detailed, deidentified patient records provided the data. Poisson regression and the Cox proportional hazards model tested six hypotheses exploring relationships between excessive MAP values and adverse outcomes. Results. The duration of vasopressor exposure, mechanical ventilation, ICU stay, and hospital stay all increased with higher MAP values (p < .0001). The risk of death within 28 days of vasopressor initiation decreased with higher MAP values (p = .0210). Conclusions. These findings will support nurses’ clinical decision-making and potentially improve outcomes in septic shock patients. Since the bedside nurse independently titrates the dose within the boundaries of the provider’s order, nursing actions significantly influence the patient’s MAP. By avoiding excessive MAP values by actively downtitrating doses when the MAP exceeds the recommended target value, four out of six adverse effects of vasopressor therapy can be mitigated, potentially improving outcomes in septic shock patients. , Nursing, Medicine, adrenergic stress, mean arterial pressure, septic shock, vasopressor titration, vasopressors, Nursing, Degree Awarded: Ph.D. Nursing. The Catholic University of America
-
- Serine Residues in Linker-2 of the Yeast Multidrug Transporter Pdr5 Modulate Drug Resistance
- Multidrug resistance to antifungals and chemotherapeutic drugs is a huge clinical problem for treatment of fungal infections and cancers. Overexpression or alteration of multidrug efflux ATP Binding Cassette (ABC) transporters is often associated with this broad-spectrum of resistance. Pleiotropic Drug Response 5 gene (PDR5) in Saccharomyces cerevisiae defines a subclass of important fungal efflux pumps. The characterization of mutations in this transporter uncovered two novel mechanism of increased resistance. The first mutation, A666G, resulted in enhanced resistance without increasing either the amount of protein in the plasma membrane or the ATPase activity. In fluorescence-quenching transport assays with rhodamine 6G in purified plasma membrane vesicles, the initial rates of rhodamine 6G fluorescence quenching of both the wild-type and mutant showed a strong dependence on ATP concentration, but were about twice as high in the latter. Plots of initial rate of fluorescence quenching versus ATP concentration exhibited strong cooperativity that was significantly increased in the A666G mutant and accounted for the observed enhancement in resistance. Alanine substitution mutations in six serine residues of linker-2 all exhibited increased resistance to xenobiotic agents. Biochemical studies of these nonsynonymous mutants demonstrated that they have increased steady-state levels of Pdr5 protein expression and thus enhanced resistance. Quantitative-RT PCR and metabolic labelling experiments demonstrated that the mutants had levels of PDR5 mRNA that were two to three times as high as in the isogenic wild-type strain because the transcript half-life was increased. These data demonstrate that the nucleotides encoding unconserved amino acids may be used to regulate expression and suggest that Pdr5 has a newly discovered RNA stability element within its coding region., Biology, Genetics, Biochemistry, ABC Transporter, Cooperativity, Linker-2, mRNA, Nonsynonymous mutation, Pdr5, Biology, Degree Awarded: Ph.D. Biology. The Catholic University of America
-
- The Servant Songs of Isaiah in the MT and the LXX: A Comparison of Their Portrayals of God
- Degree awarded: S.T.D. Biblical Studies. The Catholic University of America, This comparison of the portrayals of God in the Masoretic and Septuagint texts of the Servant Songs of Isaiah includes a discussion of the delimitation of the four songs, of text-critical issues, and of problems in translation. After the implied speakers and audiences are identified, those verses in which God is the speaker or referent are analyzed vis-à-vis their portrayal of God. The portrayals conveyed by the two forms of each song are then compared and finally patterns in differences between the Hebrew and Greek texts are identified. Although these Masoretic and Septuagint texts yield similar portrayals of God, differences emerge. The LXX texts contain fewer anthropomorphisms/anthropopathismsand depict God as more supportive of his Servant/Son than do the corresponding Masoretic texts. For example, in Isaiah 53, the MT depicts God as "crush[ing]" the Servant, whereas in the LXX the Servant's/Son's suffering is merely permitted by God, who quickly comes to his Servant's/Son's aid. The MT and the LXX texts address the problems of theodicy differently. The LXX focuses on the suffering as a divine discipline leading to wisdom while the MT gives equal weight to other explanations. For example, the Third Servant Song in the MT, unlike in the LXX, could lead the reader or listener to construe the Servant's suffering as a test of the Servant's faithfulness. While both the MT and LXX text of Isaiah 53 assert that the Servant's suffering benefits others (identified only as "we" and "the many"), the MT, unlike the LXX, does so in terms of cultic imagery. The MT, unlike the LXX text, refers to the Servant's justification of "the many." In general, the portrayal of God in the Septuagint text would appear more congenial to those Jews (and potential non-Jewish "God-fearers") influenced by Greekphilosophy. It is impossible, however, to know how the LXX translator's Vorlage compared to the MT of the Servant Songs or--to the degree that the Vorlage was the same--which of the differences in meaning were intended and not the result of errors/ambiguities in translation., Made available in DSpace on 2011-02-24T20:47:58Z (GMT). No. of bitstreams: 1 Maillet_cua_0043A_10099display.pdf: 4350893 bytes, checksum: e20db8f56ceea461ce4c316b32e61969 (MD5)
-
- Sexual-Spousal Love in the Theological Anthropology of V. S. Soloviev: Systematic Analysis and Recent Roman Catholic Interpretation
- Degree awarded: Ph.D. Historical Theology. The Catholic University of America, Sexual-Spousal Love in the Theological Anthropology of V. S. Soloviev: Systematic Analysis and Recent Roman Catholic InterpretationJohn Romanowsky, Ph.D.Director: Peter Casarella, Ph.D.This dissertation analyzes V. S. Soloviev's theological anthropology of sexual-spousal love and assesses its value as a resource for Roman Catholic theology as illustrated in the work of Angelo Cardinal Scola and Hans Urs von Balthasar.It includes the following elements. First, it presents a biography of Soloviev and an overview of the development of his theory of sexual-spousal love in all relevant texts. Second, it analyzes his methodology of "free theosophy." Third, it examines the theoretical foundations of his theory, including his Trinitarian metaphysics of "all-unity," his theology of Christ's divine-humanity, and his aesthetics of "free theurgy." Fourth, it provides an analysis of his theory of human love in general and sexual-spousal love in particular. Fifth, it assesses how Soloviev is used as a resource for contemporary Roman Catholic theological anthropology in Scola's work, The Nuptial Mystery, and von Balthasar's essay, "Soloviev" in The Glory of the Lord, identifying key positive and negative elements.Soloviev argues that the meaning of sexual-spousal love is the realization of the imago Dei or authentic personhood as revealed in "true marriage" and participates in the "great mystery" of Christ's union with the Church (Ephesians 5:32). This love is unique in its power to overcome egoism and is fulfilled in spousal union. It is the "type and ideal" of all human love. The gradual historical realization of this union in "true marriage" is a free, creative, divine-human process dependent on grace, faith, ecclesial communion, and the spiritual and moral "feat" (podvig) of the Christian life. This union will only be perfected in the fullness of the kingdom of God, the wedding of the Bride and the Lamb.Soloviev's ideas anticipate recent dogmatic and theological developments concerning spousal love and union with their emphasis on personhood, love, freedom, and communion, as well as a new focus on theological aesthetics, the former exemplified in Scola's work and the latter in von Balthasar's. Engaging Soloviev could promote progress in a Catholic understanding of sexual-spousal love and union that could help overcome tendencies to moralism, dogmatism, and the abandonment of eros to the secular culture., Made available in DSpace on 2011-06-24T17:13:36Z (GMT). No. of bitstreams: 1 Romanowsky_cua_0043A_10244display.pdf: 1846168 bytes, checksum: 22fa8f7cf4c747c1972141a315b76ab4 (MD5)
-
- The Shape of Spiritual Direction in the Mystical Theology of Jan van Ruusbroec
- This dissertation considers the trinitarian mystical theology of the late-medieval mystical theologian Jan van Ruusbroec and how his trinitarian thought forms and animates his written spiritual direction. It particularly examines the relationship between Ruusbroec’s trinitarian mystical theology and his post-Brussels written spiritual direction, which offers guidance to specific communities and persons in their pursuit of union with God through the life of prayer, worship, and service. In order to render a coherent account of this relationship and its primary characteristics, the work argues that one must read Ruusbroec as a mystical theologian. As a mystical theologian, Ruusbroec’s thought displays the natural integrity of theology and spirituality, as assumed by the majority of the theological masters of the Christian tradition, from its origins to the High Middle Ages. After dealing with the biographical details of Ruusbroec’s life and historical, cultural, and theological contexts, the study makes a foray into the works of Ruusbroec to show the primary characteristics of the Brabantine’s trinitarian mystical theology, the core of which is his teaching of essential love, the perfect, eternal simultaneity and harmony of activity and rest of the life of the Trinity. The study then goes on to offer interpretations of three of Ruusbroec’s most important writings of spiritual direction from his post-Brussels period. It shows that the Augustinian canon’s written spiritual direction in these writings is intricately shaped by his trinitarian mystical theology. His spiritual direction is, so to speak, harmonically related to the “firm melody” that is his trinitarian mystical theology. Finally, the study offers some possible paths forward for future research, based upon what the dissertation has found. The purpose of this work is to make a contribution to Ruusbroec scholarship that continues to illumine the shape, scope and beauty of his mystical theology as well as to contribute to the broader theological scholarship that has been, over the past five to eight decades, bringing to light the integrity of “spirituality” and “theology” within the Christian tradition., Theology, Spirituality, Medieval literature, Medieval, Mystical, Mysticism, Ruusbroec, Spirituality, Theology, Spirituality, Degree Awarded: Ph.D. Spirituality. The Catholic University of America
-
- "She Labored to Give Birth:" A Study of the Birth-Pangs Motif in Rev 12:2
- The birth-pang imagery of Rev 12:2 is an important part of the description of the Great Sign in Revelation 12 and draws on the varied uses of birth-pang imagery in the Bible. Revelation 12 is unique in its combination of the motifs of heavenly splendor and birth pangs. The unique significance of the birth-pang imagery for the meaning of the Great Sign can be missed if Revelation 12 is interpreted primarily in light of ancient pagan myth of even in light of the OT without the context of the NT and related literature.Birth-pang imagery in the OT is used to describe humankind's alienation from God that results from sin. The imagery is based on Gen 3:15 and developed in the prophets' writings against the infidelity of Israel. The NT use of birth-pang imagery does not emphasize negative divine judgment but the new life that follows birth pangs. Birth-pang imagery is connected to the cross and represents vicarious suffering on behalf of another's alienation from God. In the apocryphal 4 Maccabees, the suffering of the mother at the death of her sons is described as birth pangs. She is called the mother of a nation because of her strength in suffering. In Rev 12:2 the birth pangs represent the pangs of the cross and, in particular, Mary's participation in them as mother of the Messiah. Her suffering, described in terms of birth pangs, is evocative of the original birth pangs of Eve and of the trials of Israel in the exile. Furthermore, the emphasis in Revelation 12 on her maternity and her persecution by the dragon, that ancient serpent, alludes to Eve, the mother of all. Mary's heavenly splendor indicates the faithfulness that neither Eve nor Israel had. Mary is a new Eve who foreshadows the new creation of Revelation 21.The birth pangs represent Mary's suffering, which is joined to the suffering of the cross and is on behalf of her "other offspring," the faithful on earth. She is the Great Sign of the participation in the suffering and triumph of the cross to which all the faithful are invited and by which they defeat the dragon., Degree awarded: Ph.D. Biblical Studies. The Catholic University of America
-
- A Short-Term Longitudinal Study of the Adjustment of Foster Youth Across the Aging Out Transition and the Benefit of Life Skills Training
- Degree awarded: Ph.D. Psychology. The Catholic University of America, Background: Annually, 30,000 youth in the U.S. emancipate out of foster care (age out) as adults. For many foster youth, the aging out process is a move to complete independence, with no additional support from the government or parental caregivers. Currently, there is little research examining the course of adjustment of youth aging out of care. Given the lack of supports, there is a genuine question of whether many foster youth can make a successful transition to adulthood. Objective: The current research examined the short-term psychological and societal outcomes of emancipated foster youth. In addition, life skills training (LST) and life skills knowledge (LSK) were assessed to determine whether they predicted better outcomes after emancipation. Method: 23 foster youth participated at Time 1 (3 months prior to emancipation) and 13 participated at T2 (3 months after emancipation), utilizing a prospective longitudinal design. All completed multiple self-report questions and an interview of informal life skills training. Results: Social support significantly decreased from T1 to T2, but other psychological measures did not show evidence of negative changes across the transition. Formal LST predicted a reduction in trauma symptoms regarding relationships with others. Informal LST predicted better adjustment on a number of societal variables, including having a bank account, driver's license, or a cell phone. LSK predicted a number of psychological and societal variables, including decreased PTSD and associated trauma symptoms, and having a driver's license or car. However, LSK at time 1 was not a mediator between LST at T1 and psychological or societal variables at time 2. Conclusions: Results provide initial data on the immediate transitional process of emancipating foster youth. The conclusions are limited by low statistical power to detect significant effects. The findings indicate that the aging out transition is marked by reductions in social support, but may not be associated with other psychological problems, at least over the initial months. LSK appeared to aid in making a successful transition for foster care alumni, indicating that it may be an important target of prevention programs. However, fewer findings were obtained for LST. More work is needed to determine whether particular components of LST programs are more or less beneficial for foster youth. Future research should develop a "gold standard" by which other LST programs can be evaluated against. Further, prospective longitudinal research is needed with larger samples in order to identify the factors that contribute to risk and resilience across the aging out process., Made available in DSpace on 2014-02-11T18:36:07Z (GMT). No. of bitstreams: 1 Smith_cua_0043A_10457display.pdf: 2430474 bytes, checksum: 126d876c273e487a5f94c26763cd7aca (MD5)
-
- Silence Through Representation: La Malinche as Christian, Mistress, and Conquistadora
- Degree awarded: Ph.D. Spanish. The Catholic University of America, Silence Through Representation: La Malinche as Christian, Mistress andConquistadoraColleen A. Sweet, Ph.D.Director: Mario A. Ortiz, Ph.D.La Malinche played a major role in the Mexican Conquest. She is known as both mistress and translator of Hernán Cortés. In Mexican history, her name is associated with betrayal. The year 1992 was pivotal in the discourse concerning the encounter between Europe and the Americas. Postcolonial studies stressed the need to recover the long-silenced voice of the subaltern characters of the Conquest. This search for an indigenous perspective inspired a new body of artistic works concerning Malinche. In this dissertation I examine the film La otra conquista (Salvador Carrasco, 1998), the novel Malinche (Laura Esquivel, 2006), and the play La Malinche (Víctor Hugo Rascón Banda, 2000). These works address three major roles associated with the representation of Malinche: as convert to Christianity, as mistress to Cortés, and as collaborator in the events of the Conquest. The works under study posit new explorations into the role of both female and indigenous figures in the discourse of the Conquest of Mexico. In La otra conquista, Carrasco removes Malinche from the historical record and replaces her with a revisionist figure. The character of Isabel Moctezuma subverts the traditional representation of Amerindian female women as passive victims of Mexico's colonial past. In her novel Malinche, by turning Malinche into a romance heroine not only does Esquivel silence her, she also perpetuates a model of passivity for Amerindian women. In La Malinche, Rascón Banda fragments Malinche into many different characters in order to parallel the political divisiveness plaguing Mexico after the crisis of 1994. Malinche is an ever-changing palimpsest that serves to broach the issues of Mexican, Latin American, feminine, and indigenous identity that each author wishes to revisit. The representations of Malinche in these works remind us that the relationships of domination and subordination from our historical past still echo today. Thus, Malinche's silence underscores the impossibility of rescuing the subaltern from historical obscurity., Made available in DSpace on 2012-02-15T20:54:48Z (GMT). No. of bitstreams: 1 Sweet_cua_0043A_10280display.pdf: 724732 bytes, checksum: 0b4699b259f1438406178233c4e60fa7 (MD5)
-
- Silent Idol, Speaking Text: Prophetic Writing as Material Mediation of Divine Presence
- This study focuses on the writtenness of the books of Jeremiah, Ezekiel and Isaiah as effecting the prophetic message of divine presence.The books of Jeremiah, Ezekiel and Isaiah site themselves in times of significant trauma, contexts in which the question of the presence of the LORD was of critical import. Their response is analyzed through the interleaving of three strands of research pertaining to the Ancient Near East: the process of prophecy as mediation of divine messages; the construction of divine presence, including the mīs pî (mouth-opening) ritual through which cult images were imbued with divine presence; and the practices and meanings of writing, including the signifying effect of its materiality and the interrelationship of inscription and orality.The question of divine presence, and its reverse, absence, is explicitly presented in passages such as Jeremiah’s threats of Jerusalem’s doom and Ezekiel’s encounter with the glory of the LORD and witness to the withdrawal of that glory from the Temple. The issue is further implicated in the books’ treatment of divine images – those material forms that purport to presence divinity. The books invert the mīs pî, whether in depicting the empty no-things of the nations or the emptiness Israel and Judah became through their own falseness, clinging to dead stone and cracked cisterns rather than drinking in the living LORD. Yet the mīs pî is positively evoked in application to the prophets Isaiah, Jeremiah and Ezekiel, presenting the prophetic personae as authentic mediators of divine presence. Each has a transformational encounter with the LORD through which his mouth is opened. The divine word is taken in and is returned again as written text. The transformed body of the mouth-opened prophet becomes the transforming body of the mouth-opening scroll. Divine presence is realized anew through this mutually reviving intersection of written and reading bodies, as the lector’s breath reanimates the text’s bones., Biblical studies, critical space theory, divine presence, prophetic books, prophets, writing, Biblical Studies, Degree Awarded: Ph.D. Biblical Studies. The Catholic University of America
-
- Single molecule characterization of the elastic response of DNA & DNA-histone complexes using horizontal magnetic tweezers
- We describe single molecule experiments carried out using a modified semi-closed, horizontal magnetic tweezers capable of generating high-resolution DNA extension and force data. We discuss numerous modifications to the instrument which in conjunction with the Allan variance (AV) and power spectral density (PSD) approaches to force calibration allowed us to reliably measure forces in a wide range, from ~ 0.01 pN to ~110 pN and higher. Instrument-related developments include a new cleaning protocol, the determination of appropriate bead-DNA ratios, a new method for fitting micropipettes to Tygon tubes, a simple solution to prevent sample cell deformation, a new method for pipette insertion into the sample cell, as well as the first steps toward real-time data processing using parallel computing approaches. Using the tweezers, we studied the mechanical properties of arrays of nucleosomes reconstituted from native histones. We applied forces on DNA-histone complexes from ~ 2 pN to ~ 80 pN, and found that octameric complexes were destabilized with step-like increments in tether extension. The majority of disruption lengths were found to be integer multiples of ~ 50 nm. We assayed the mechanical response of histone-compacted DNA tethers by gradually increasing the force at a loading rate of ~ 0.008 pN/s. In a related set of studies, compacted tethers were subject to constant forces over an extended period of time. We determined that a minimum force of ~ 2.5 pN was required to destabilize nucleosomes. We then analyzed the effect of histone acetylation on the mechanical stability of nucleosome arrays by performing micromanipulation experiments on tethers reconstituted using hyperacetylated histones. Our data show that hyperacetylated nucleosomes require an unbinding force of around ~ 2.5 pN, which is similar to that required for native histones. Moreover, we identified clear differences between the step size distributions of native and hyperacetylated histones and found that in contrast to tethers reconstituted with native histones, the majority of nucleosomes in tethers compacted with hyperacetylated histones underwent disassembly at forces significantly lower than 6 pN. Our micromanipulation data also showed that hyperacetylated histones were more likely to rupture simultaneously than native histones at all force ranges., Physics, Biophysics, Physics, Degree Awarded: Ph.D. Physics. The Catholic University of America
-
- Skyrmions in Magnetic Multilayers
- As technology has ceaselessly advanced, transistors have reached ever smaller sizes and higher densities, which has led to smaller and more powerful devices and electronics, however now we face new problems arising from this shrinking size scale and increasing density. As transistor density increases, efficiency and heating effects are increasingly becoming unsolved problems. In addition, modern transistors are now being fabricated with sizes small enough to reach their innate physical limitations, specifically where the different rules of quantum physics apply. These issues and others indicate the need for novel devices and systems that operate via different mechanisms. One such potential avenue of study is the field of skyrmionics, which pertains to the study of systems and devices which operate using magnetic skyrmions. Magnetic skyrmions are nanoscale, topologically protected, quasiparticles that present a new paradigm as potential information carriers in next generation low-power, high-density memory and storage devices. These stable excitations of the local magnetization of their host materials importantly only manifest in particular systems, such as multilayer thin film systems. Both symmetric and asymmetric multilayer thin film systems have been shown to host magnetic skyrmions at room temperature in the absence of any applied field. These novel system types, in particular the heavy metal/ultra-thin ferromagnet/heavy metal system types, present great interest due to their ability to host magnetic skyrmions, as well as potentially drive them efficiently using a novel driving mechanism which operates via the use of spin-orbit torques. In this thesis, we will explore three such potential magnetic skyrmion hosting multilayer thin film systems: Pd/Co/Pd, Pt/Co/Pt, and Pd/Co/Pt multilayer systems. In order to tune the iDMI strength and obtain a range of magnetization orientation morphologies, we vary the thickness of the Co ferromagnet layer, which allows us to determine the conditions under which magnetic skyrmions manifest. We used molecular beam epitaxy in an ultra-high vacuum environment to fabricate the multilayer thin film samples, and subsequently physically and magnetically characterize them via various methods. We also used magnetic and atomic force microscopy to characterize and confirm the magnetic domains present, and thus confirm the presence of magnetic skyrmions in each multilayer system studied. In addition, we complete a methodical micromagnetic simulation study of these three multilayer systems using MuMax3. These simulations are compared to the physical results in order to estimate the iDMI and other parameters of the various domain morphologies present, including those hosting magnetic skyrmions., Condensed matter physics, Nanotechnology, Materials Science, Magnetic Domains, Magnetic Skyrmions, Micromagnetic Simulation, Molecular Beam Epitaxy, Multilayer, Skyrmions, Physics, Degree Awarded: Ph.D. Physics. The Catholic University of America
-
- Sleep Disturbances and Family Environment Correlates in Children with Generalized Anxiety Disorder
- Degree awarded: Ph.D. Psychology. The Catholic University of America, Background: A growing empirical literature supports that sleep problems are prevalent among clinically anxious youth. Children with generalized anxiety disorder (GAD) report especially high rates of sleep problems yet systematic investigation of the specific nature of sleep disturbances through both objective and subjective sleep measures is unavailable in non-depressed children with primary GAD. Research suggests that overlapping biological and environmental risk factors underlie the complex bidirectional relationship between sleep and anxiety; however identification of potentially modifiable environmental risk factors for sleep disturbance in pediatric GAD, including family and parenting factors, is also lacking. Objective: To address these gaps and identify potential intervention targets specific to pediatric GAD, the current study examines specific sleep problems and proposed family correlates in non-depressed pre-pubescent children with primary GAD as compared to their healthy peers utilizing both actigraphy and parent-reported measures of sleep. Method: 52 children (ages 7-11 years), including 29 with GAD and 23 healthy controls, participated. All underwent structured diagnostic assessment. Parents and children reported on family factors. Sleep was assessed via actigraphy and a standardized parent-report questionnaire. Results: Children with GAD showed significantly increased parent-reported difficulties with sleep onset delay, sleep anxiety, bedtime resistance and parasomnias compared to controls. In contrast, children with GAD did not demonstrate significantly greater actigraphy-measured sleep problems than the control group. Data also indicate that parental psychological control and over-involvement in children's sleep (e.g. increased reassurance and co-dependent sleep) were especially deleterious for sleep in children with GAD. Conclusions: Results add to a growing body of literature linking reported sleep problems to pediatric GAD. The apparent discrepancy between objective and subjective sleep measures in this clinical sample underscores the importance of considering how these measures may quantify different aspects of sleep and provide unique information relevant to pediatric GAD. Findings suggest that parent psychological control and certain sleep-related parenting strategies may be especially important to consider in the treatment of sleep problems in pediatric GAD. Follow-up studies in larger samples are needed to replicate data and to examine whether targeting specific sleep problems or parenting strategies early in the course of GAD might improve clinical outcomes., Made available in DSpace on 2013-11-05T15:05:20Z (GMT). No. of bitstreams: 1 Zakarin_cua_0043A_10441display.pdf: 870278 bytes, checksum: 3f0c31082a7e08708fbe41e7e9b0d2f3 (MD5)