454 research outputs found
Speech perception and localization abilities in pediatric bilateral sequential cochlear implant recipients
The primary purpose of this study was to evaluate speech perception and localization abilities in children who have received sequential cochlear implants, with the first implant received before age 4 and the second implant received before age 12. Results indicate performance in the bilateral cochlear implant condition is significantly better than listening with each implant alone for the outcome measures used in this study
Trophectoderm mechanics direct epiblast shape upon embryo implantation
Implantation is a hallmark of mammalian embryogenesis during which embryos establish their contacts with the maternal endometrium, remodel, and undertake growth and differentiation. The mechanisms and sequence of events through which embryos change their shape during this transition are largely unexplored. Here, we show that the first extraembryonic lineage, the polar trophectoderm, is the key regulator for remodeling the embryonic epiblast. Loss of its function after immuno-surgery or inhibitor treatments prevents the epiblast shape transitions. In the mouse, the polar trophectoderm exerts physical force upon the epiblast, causing it to transform from an oval into a cup shape. In human embryos, the polar trophectoderm behaves in the opposite manner, exerting a stretching force. By mimicking this stretching behavior in mouse embryogenesis, we could direct the epiblast to adopt the disc-like shape characteristic of human embryos at this stage. Thus, the polar trophectoderm acts as a conserved regulator of epiblast shape
The Invasive Potential of \u3ci\u3eElaeagnus angustifolia\u3c/i\u3e in the Natural Pastures of the Rio Negro Valley, Argentina
From awareness to advocacy: understanding communication about cancer and nonprofit support
This dissertation explores public communication about and support for nonprofit health organizations by studying a specific community fundraising event, Relay For Life, benefiting the American Cancer Society. Using an online survey of undergraduates at the University of North Carolina at Chapel Hill (N=514), this research has two major focuses. First, it seeks to explore the concepts of media advocacy and framing as they are changing with the media environment. Second, it employs two theories, the situational theory of publics and the theory of reasoned action, to explore communication and participation behaviors related to the health issue and organization. Results show which sources are used most frequently for information seeking and processing about cancer and UNC Relay For Life, and responses reveal salient public perceptions of these issues. Multiple analyses then show how problem and constraint recognition, involvement with the health issue, attitudes, and subjective norms influence information seeking and processing and behavioral intentions, which seem to represent a continuum of nonprofit support. Suggestions are made for exploring a new working model combining these variables and a proposed Theory of Situational Support that might help explain communication and participation behaviors related to nonprofit health organizations and events or initiatives that require public support. Theoretical, methodological, and practical implications are discussed
Constituting decadence: Anglophone modernist fiction and the politics of federation, 1880-1980
This dissertation provides the first critical account of modernism as a constitutional culture. I explore how key Anglophone modernists responded to the emergence of federal governance as a national norm and international ideal, with particular focus on the movement for British imperial federation and the forms of postcolonial governance it influenced during the twentieth century. Intervening in recent methodological debates over the social effects of literary form, I develop an interdisciplinary analysis of literature's relationship to informal constitutional change and write literary history as alternative constitutional history. Through close reading and original historical and archival research, I show how writers incorporated federalism's logic of plural perspectives and distributed sovereignty while also registering unacknowledged forms of racial apartheid, or what Edward Kamau Brathwaite calls “negative federation.”
By identifying modernist fiction’s critical relationship to liberal federalism, I argue that modernism’s distinctive formal disruptions mediated the changing constitutional form of states across the Anglophone world. My introduction surveys the Anglo-American discourse of federation and defines the study’s central concepts of racial capitalism, modernist formal decadence, and informal constitutional change. Chapter one explores ways in which Oscar Wilde's study of political philosophy and his 1882 visit to the southern United States influenced his critical views on imperial federation and his development of the gothic Bildungsroman as a means of portraying metropolitan constitutional corruption. Chapter two places Virginia Woolf's novels on the timeline of constitutional reforms that prolonged British rule in India, demonstrating that her characters' identity crises and her invention of a style of modernist national biography reflected attempts to redefine the Empire as a quasi-federal Commonwealth. Chapter three analyzes the historical and romance elements in William Faulkner’s fiction, arguing that his attention to liberal federalism’s economic foundations produces a collection of constitutional apocrypha that disrupts the perspectives and assumptions of white supremacy. The conclusion sketches liberal federalism’s postcolonial trajectories through case studies of Joseph Conrad, Jean Rhys, Claude McKay, Ralph Ellison, and Salman Rushdie. The narratives I examine indicate modernist fiction’s ability to amplify what modern political theory refers to as “constituent power”: the disruptive influence of subjects who have been excluded from the liberal state’s formally constituted power
Integrin beta 1 coordinates survival and morphogenesis of the embryonic lineage upon implantation and pluripotency transition
At implantation, the embryo establishes contacts with the maternal endometrium. This stage is associated with a high incidence of preclinical pregnancy losses. While the maternal factors underlying uterine receptivity have been investigated, the signals required by the embryo for successful peri-implantation development remain elusive. To explore these, we studied integrin beta 1 signaling, as embryos deficient for this receptor degenerate at implantation. We demonstrate that the coordinated action of pro-survival signals and localized actomyosin suppression via integrin beta 1 permits the development of the embryo beyond implantation. Failure of either process leads to developmental arrest and apoptosis. Pharmacological stimulation through fibroblast growth factor 2 (FGF2) and insulin-like growth factor 1 (IGF1), coupled with ROCK-mediated actomyosin inhibition, rescues the deficiency of integrin beta 1, promoting progression to post-implantation stages. Mutual exclusion between integrin beta 1 and actomyosin seems to be conserved in the human embryo, suggesting the possibility that these mechanisms could also underlie the transition of the human epiblast from pre- to post-implantation
Morphogenesis of extra-embryonic tissues directs the remodelling of the mouse embryo at implantation
Abstract: Mammalian embryos change shape dramatically upon implantation. The cellular and molecular mechanism underlying this transition are largely unknown. Here, we show that this transition is directed by cross talk between the embryonic epiblast and the first extra-embryonic tissue, the trophectoderm. Specifically, we show via visualisation of a Cdx2-GFP reporter line and pharmacologically mediated loss and gain of function experiments that the epiblast provides FGF signal that results in differential fate acquisition in the multipotent trophectoderm leading to the formation of a tissue boundary within this tissue. The trophectoderm boundary becomes essential for expansion of the tissue into a multi-layered epithelium. Folding of this multi-layered trophectoderm induces spreading of the second extra-embryonic tissue, the primitive endoderm. Together, these events remodel the pre-implantation embryo into its post-implantation cylindrical shape. Our findings uncover how communication between embryonic and extra-embryonic tissues provides positional cues to drive shape changes in mammalian development during implantation
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