48 research outputs found
Evolutionary development of the plant and spore wall
The article provides an overview of the development and structure of spore and pollen walls in the major plant groups and summarises progress in our understanding of the molecular genetics underpinning spore/pollen evolution and development
Time lapse: The politics of time -travel cinema
My dissertation explores the relationship between temporality and subjectivity through the genre of time-travel cinema. While many theorists, including Anne Friedberg, D. N. Rodowick, and Constance Penley have pointed out that cinema has the properties of a time machine, few film theorists have systematically considered the significance of this observation for thinking about modern and postmodern constructions of time, history, and memory as they are produced cinematically. In its analysis of time-travel cinema, my project not only considers time travel\u27s ability to reflect the transformation of the subjective experience of time within modernism and postmodernism, but also identifies the genre\u27s utopian imagination, through the time traveler\u27s ability to change the course of history. In order to develop my theory of modern experience, I consider Walter Benjamin\u27s claims about Surrealism and modernity in a cinematic context, arguing that time-travel narratives can offer a profound critique of everyday experience. This imagination is, however, frequently confronted by a more powerful, homeostatic drive to preserve the existent world and, by implication, the current social order. I also trace the various ideological implications of nostalgia films within the time-travel genre before turning to constructions of subjectivity in alternate-reality films. I then focus on the role of post-cinematic technologies in presenting another threat to the stable subject before culminating with an analysis of Chris Marker\u27s Sans Soleil, which I read as an avant-garde time-travel film
John Doe\u27s Wallet and Jane Doe\u27s Purse Look at Hometown Recycling and Energy Conservation
A national shift from the use of virgin raw materials to greater use of recycled raw materials could significantly reduce our nation\u27s energy needs. Local governments are slowly but increasingly establishing solid waste recycling programs, but they are commonly operated as add ons to the existing solid waste disposal system rather than being an integral part of it. The result is both energy and monetary waste, and the taxpayers have to pick up the bill. A case study from Rolla, Missouri, quantifies the energy conservation and monetary costs and benefits of a coordinated solid waste disposal-recycling system
Lineage relationship of direct-developing melanocytes and melanocyte stem cells in the zebrafish.
Previous research in zebrafish has demonstrated that embryonic and larval regeneration melanocytes are derived from separate lineages. The embryonic melanocytes that establish the larval pigment pattern do not require regulative melanocyte stem cell (MSC) precursors, and are termed direct-developing melanocytes. In contrast, the larval regeneration melanocytes that restore the pigment pattern after ablation develop from MSC precursors. Here, we explore whether embryonic melanocytes and MSCs share bipotent progenitors. Furthermore, we explore when fate segregation of embryonic melanocytes and MSCs occurs in zebrafish development. In order to achieve this, we develop and apply a novel lineage tracing method. We first demonstrate that Tol2-mediated genomic integration of reporter constructs from plasmids injected at the 1-2 cell stage occurs most frequently after the midblastula transition but prior to shield stage, between 3 and 6 hours post-fertilization. This previously uncharacterized timing of Tol2-mediated genomic integration establishes Tol2-mediated transposition as a means for conducting lineage tracing in zebrafish. Combining the Tol2-mediated lineage tracing strategy with a melanocyte regeneration assay previously developed in our lab, we find that embryonic melanocytes and larval regeneration melanocytes are derived from progenitors that contribute to both lineages. We estimate 50-60 such bipotent melanogenic progenitors to be present in the shield-stage embryo. Furthermore, our examination of direct-developing and MSC-restricted lineages suggests that these are segregated from bipotent precursors after the shield stage, but prior to the end of convergence and extension. Following this early fate segregation, we estimate approximately 100 embryonic melanocyte and 90 MSC-restricted lineages are generated to establish or regenerate the zebrafish larval pigment pattern, respectively. Thus, the dual strategies of direct-development and MSC-derived development are established in the early gastrula, via fate segregation of the two lineages
Prices and costs in manufacturing industries,
At head of title: 86th Cong., 2d sess. Joint Committee print.Mode of access: Internet