27 research outputs found
Spacecraft design project: Low Earth orbit communications satellite
This is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration 2 course (AE-4871) taught at the U.S. Naval Postgraduate School. The Spacecraft Design and Integration 2 course is intended to provide students detailed design experience in selection and design of both satellite system and subsystem components, and their location and integration into a final spacecraft configuration. The design team pursued a design to support a Low Earth Orbiting (LEO) communications system (GLOBALSTAR) currently under development by the Loral Cellular Systems Corporation. Each of the 14 team members was assigned both primary and secondary duties in program management or system design. Hardware selection, spacecraft component design, analysis, and integration were accomplished within the constraints imposed by the 11 week academic schedule and the available design facilities
Dynamic genome evolution in a model fern
The large size and complexity of most fern genomes have hampered efforts to elucidate fundamental aspects of fern biology and land plant evolution through genome-enabled research. Here we present a chromosomal genome assembly and associated methylome, transcriptome and metabolome analyses for the model fern species Ceratopteris richardii. The assembly reveals a history of remarkably dynamic genome evolution including rapid changes in genome content and structure following the most recent whole-genome duplication approximately 60 million years ago. These changes include massive gene loss, rampant tandem duplications and multiple horizontal gene transfers from bacteria, contributing to the diversification of defence-related gene families. The insertion of transposable elements into introns has led to the large size of the Ceratopteris genome and to exceptionally long genes relative to other plants. Gene family analyses indicate that genes directing seed development were co-opted from those controlling the development of fern sporangia, providing insights into seed plant evolution. Our findings and annotated genome assembly extend the utility of Ceratopteris as a model for investigating and teaching plant biology
Eco-politics beyond the paradigm of sustainability: A conceptual framework and research agenda
This contribution sketches a conceptual framework for the analysis of the post-ecologist era and outlines a research agenda for investigating its politics of unsustainability. The article suggests that this new era and its particular mode of eco-politics necessitate a new environmental sociology. Following a review of some achievements and limitations of the paradigm of sustainability, the concept of post-ecologism is related to existing discourses of the âend of natureâ, the âgreen backlashâ and the âdeath of environmentalismâ. The shifting terrain of eco-politics in the late-modern condition is mapped and an eco-sociological research programme outlined centring on the post-ecologist question: How do advanced modern capitalist consumer democracies try and manage to sustain what is known to be unsustainable
Counting Carbon: Calculative Activism and Slippery Infrastructure
The environmental movement in the global North is in a state of impasse. It appears that despite the renewed international focus on climate change, and the actions of innumerable social movements, a âsolutionâ to the problem appears as one, without a viable solution. It is the contention of this paper that climate change has no clearly viable solution as it is a seemingly impossible problem. This paper investigates how the problem of climate change is constructed as a global object of political action and how it functions to render politics into a matter of calculative action, one that seeksâbut failsâto take hold of a slippery carbon infrastructure. It concludes by suggesting one possible solution to this dilemma is to turn away from the global scalar logic of climate change and towards a situated focus on questions of infrastructure, or what Dimitris Papadopoulos calls âthick justiceâ
Spacecraft Design Project Low Earth Orbit Communications Satellite
AE-4871 Advance Spacecraft DesignNASA-CR-192038This report is the final product of the spacecraft design project completed to fulfill
the academic requirements of the Spacecraft Design and Integration II course (AE-4871)
taught at the U.S. Naval Postgraduate School.NASA/Universities Space Research Association Advanced Design Progra
Climate change ethics, rights and policies; An introduction
Climate change continues to dominate academic work within green/environmental politics. Indeed, there appears to be almost an inverse relationship between the lack of political leadership on tackling climate change and the growth in ever more sophisticated academic analyses of this complex and multifaceted problem. There is an increasing disjunction between the growth in our knowledge and understanding of the ethical, political, economic, sociological, cultural, and psychological aspects of climate change and the lack of political achievement in putting in place clear and binding targets, an agreed decarbonisation roadmap, and associated regulatory and policy instruments with enforcement. This gap might be taken as evidence that we do not need more reports on climate change. To quote that most unlikely of green politicians, Arnold Schwarzenegger, former Governor of California: âThe debate is over. We know the science. We see the threat. And we know that the time for action is nowâ (California Energy Commission 2007, p. 1). This special issue focuses on a variety of ways in which climate change is conceptualised in normative political and ethical theory, and addressed in policy and regulations