1,587 research outputs found

    Integration of a supersonic unsteady aerodynamic code into the NASA FASTEX system

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    A supersonic unsteady aerodynamic loads prediction method based on the constant pressure method was integrated into the NASA FASTEX system. The updated FASTEX code can be employed for aeroelastic analyses in subsonic and supersonic flow regimes. A brief description of the supersonic constant pressure panel method, as applied to lifting surfaces and body configurations, is followed by a documentation of updates required to incorporate this method in the FASTEX code. Test cases showing correlations of predicted pressure distributions, flutter solutions, and stability derivatives with available data are reported

    Doctor of Philosophy

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    dissertationThere are many bacteria that associate with insects in a mutualistic manner and offer their hosts distinct fitness advantages, and thus have likely played an important role in shaping the ecology and evolution of insects. Therefore, there is much interest in understanding how these relationships are initiated and maintained and the molecular mechanisms involved in this process, as well as interest in developing symbionts as platforms for paratransgenesis to combat disease transmission by insect hosts. However, this research has been hampered by having only a limited number of systems to work with, due to the difficulties in isolating and modifying bacterial symbionts in the lab. In this dissertation, I present my work in developing a recently described insect-bacterial symbiosis, that of the louse fly, Pseudolynchia canariensis, and its bacterial symbiont, Candidatus Arsenophonus arthropodicus, into a new model system with which to investigate the mechanisms and evolution of symbiosis. This included generating and analyzing the complete genome sequence of Ca. A. arthropodicus, which provided some evidence that Ca. A. arthropodicus has become recently associated with insects and may have evolved from an ancestor that was an insect pathogen. Additionally, I describe the development of methods for genetic modification of this bacterial symbiont and for introducing recombinant symbionts into louse fly hosts, as well as a new microinjection technique that enables the complete replacement of native symbionts with recombinant symbionts. With the generation of the symbiont genome sequence along with strategies for engineering recombinant symbionts and establishing them in an insect host, this work provides an interesting new system with which to investigate the function of specific genes in symbiosis as well as a promising new avenue of research involving paratransgenesis

    Sheltering Opportunity: City Planning and Housing in Chicago, 1909-1941

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    City planning in the United States has undergone continuous evolution; the profession has struggled to produce solutions that match the caliber of its ambitions while keeping up with the ever-changing city. Furthermore, at times special interests have co-opted city planning, utilizing and constraining the profession to meet those interests – often focused on increasing property values while neglecting other social needs, not least of which is the provision of adequate housing. This dissertation aims to contribute to a better understanding of how the definition and scope of city planning changes to include or exclude social issues by examining the relationship between city planning and housing in Chicago from 1909 to 1941 through the lens of the Chicago Plan Commission. This research argues that the motivation to change alone – particularly from peripheral movements like that of housing – is not sufficient; in the absence of the need or opportunity to change, the status quo is likely to persist. When the luxury of maintaining the status quo is removed, the likelihood of change increases significantly. We also see that who and what are involved in the initial development of city planning has long-term consequences. What the scope of city planning includes is largely dependent upon those initial players – in the case of Chicago, the city’s elite business interests. This research argues that those actors were able to establish city planning along narrow lines, limited to their understanding and perspective on what city planning could and should be, lines that were deeply reinforced and difficult if not impossible to shift. This research also argues that, when the opportunity for change emerges, who is present and prepared to make demands on city planning is important, as they can successfully influence its shape and scope – for early planning in Chicago, this came in the form of the Metropolitan Housing Council. Finally, this dissertation asserts that there is value in more closely examining change and stasis via the lens of the city plan commission, a constant entity in city planning whose role and function can serve as an indicator of the state of city planning

    Old French borrowings in The Owl and the Nightingale

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    Old French Borrowings in The Owl and the Nightingale ascertains the quantity and nature of Old French words present in this thirteenth-century Middle English poem. Patterns of borrowing, whether source-based or subject-based, are identified and problematic words, such as cognates, are investigated for probable language of origin. These patterns are then examined for what they may reveal about the author and audience of The Owl and the Nightingale. Included is an appendix listing each borrowed term and cognate in alphabetical order with definitions and parts of speech

    The role of research in teacher education

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    The current paper will briefly elaborate on the understanding of the concept ‘research-based’ teacher education and discuss what type of research teacher education and teacher educators can chiefly benefit from. I argue that developing teacher educators’ research competence is a neglected challenge and so is the need for protected time for teacher educators to engage in research

    The Janus faced teacher educator

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    This paper focuses on the Janus face-teacher educator and researcher. Drawing on existing international literature, our aim is to position ourselves in the discussion relating to our own and other research. In this paper we limit ourselves to discuss two main components, namely teaching and research in relation to which teacher educators seem to experience a rather strong tension. We maintain that the quality of teaching does not become inferior to research and publishing in teacher education. This necessitates that sufficient resources are provided for assuring the quality of teaching and for research; subsequently the two activities are complementary and not contradictory to each other. Our claim is that teacher educators in most settings are Janus-faced due to the competing demands of excellence in both research and teaching. However, we strongly believe that the two main responsibilities of teacher educators which form the Janus face, can melt into each other in the face of a researching teacher educator.Portuguese national funds through the FCT (Foundation for Science and Technology) within the framework of the CIEC (Research Center for Child Studies of the University of Minho) project under the reference UID/CED/00317/201

    Increasing the Use of Practical Activities through Changed Practice

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    This study sets out to examine the influence of a value-based intervention on two elementary school teachers’ use of practical activities in mathematics teaching. The intervention was a “Values and Knowledge Education” (VaKE)-based in-service course that introduced the two teachers to a value-based approach to mathematics teaching. The introduction included examples that were supported by use of practical activities. Interviews prior to the intervention made the teachers aware of an inconsistency between the desired and actual practice of their own teaching. The intervention provided them with a possibility of narrowing the gap between vision and practice by changing practice. Qualitative data show how the VaKE approach offered an alternative that opened up for increased use of practical activities in the teaching of mathematics, but also showed how good intentions of changing practice might be restrained or hindered by beliefs and previous experience

    Expression of a human cartilage procollagen gene (COL2A1) in mouse 3T3 cells.

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    Expression in a recombinant system has been difficult to obtain for any of the major fibrillar collagens that require processing by eight or more post-translational enzymes. Here, two DNA constructs were designed so that the promoter region of the gene for the pro-alpha 1(I) chain of human type I procollagen drove expression of the human type II procollagen gene in mouse NIH 3T3 cells, a culture line that normally synthesizes type I procollagen but not any cartilage-specific protein such as type II procollagen. Both constructs were expressed as both mRNA and protein. In clones expressing the construct at high levels, the steady-state levels of mRNA and the production of type II procollagen were comparable to the mRNA levels and production of type I procollagen from the endogenous mouse genes. Comparison of clones containing the two constructs demonstrated that sequences extending 80 base pairs beyond the major polyadenylation signal of the gene are not in themselves sufficient for correct termination and 3\u27 processing of RNA transcripts. The results strongly suggest that specific sequences present in a downstream 3.5-kilobase SphI/SphI fragment determine the termination of the transcription. Of special importance is that the system will make it possible to examine the consequences of mutations in the human type II procollagen gene on the processing of RNA transcripts and on the functional properties of the protein simply by using the genomic DNA from leukocytes or other non-cartilaginous sources

    Entrance into teaching and need for support – narratives from diverse national and local contexts

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    Denne studien undersøker hvordan en gruppe nye lærere i ulike nasjonale og lokale sammenhenger erfarer inngangen til læreryrket. Studien er basert på narrativer fra nye lærere i Australia, England og Norge. Ved å lytte til deres fortellinger, er målet å utvikle en forståelse for denne spesifikke fasen i læreres profesjonelle liv og å lære mer om hvordan nyutdannede kan støttes. Funnene indikerer at det på tvers av de aktuelle nasjonene er flere likheter enn forskjeller knyttet til inngangen til lærerprofesjonen. Når det gjelder støtte, er behovene mye de samme, men rammene rundt veiledning og annen støtte er forskjellige. Studien impliserer at det er likheter som gjør det mulig å lære av hverandre når det gjelder rammeverket for støtte og veiledning og når det gjelder hva som bidrar til profesjonell utvikling på tvers av nasjonale kontekster.publishedVersio

    Dietary Overlap of American Barn Owl and Short-Eared Owl in the Mission Valley, Montana

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    The Mission Valley is home to many species of wildlife, including the Short-eared owl.  Over the last decade Barn Owl sightings have increased in the valley and nests have been discovered.  We analyzed food-niche overlap between American Barn Owls (Tyto furnata) and Short-eared Owls (Asio flammeus) over one year to determine whether prey competition from the local Barn Owl population will affect the Short-eared Owl population. A total of 325 prey items (11 different species) were identified from 152 pellets; 79 Barn Owl and 73 Short-eared Owl.  Diets of both species consisted primarily of Microtus species, although traces of additional food resources were present. Using Pianka’s index the food-niche overlap was 0.658, where Pianka’s index determines what proportion of the two owl species’ diets overlap with a value of 0 representing total separation and a value of 1 representing total overlap.  The results of this study showed a food niche overlap between the two owl species. We suggest, however, that the current population of Barn Owl in the Mission Valley is not directly competing with the established Short-eared Owl population in the Mission Valley, given th
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