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Mechanisms of floor plate formation in the developing chick embryoPatten, Iain January 2002 (has links)
No description available.
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Analysis and interpretation of full waveform sonic dataAstbury, S. January 1985 (has links)
No description available.
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Gaining public acceptance of the sonic boom phenomenon through public relationsMartin, William H. January 1963 (has links)
Thesis (M.S.)--Boston University / Public relations probably can do more to gain public tolerance
of a phenomenon such as the sonic boom than any other procedure or
proqram that might be undertaken by a service or commercial organization.
This study attempts to show how the United States Air Force
has applied an intense program of public relations toward that goal.
T11e Air Force campaign of briefings, publicity, and handling
of citizens' complaints was -investigated through inspection of Air
Force official records and joint Air Force-commercial campaign
materials.
The methods currently used were found to be generally effective,
with some parts more effective than others.
The findings of this study may be of interest to commercial
airlo.nes for assistance in planning their own approach to the
problem when supersonic airliners are put into general use.
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Chromatin dynamics at the Sonic Hedgehog locus : a study using limb derived Sonic Hedgehog inducible cell lines to investigate chromatin architectureDouglas, Adam Thomas January 2017 (has links)
Enhancers are cis-regulatory sequences which promote the expression of target genes in a spatial and temporal fashion. They can be located within genes or between them and can act at distances of over 1 Mb. There are several different mechanisms by which enhancers regulate gene expression. Some, such as those regulating the Hox genes, are located close to each other in the genome in a structure referred to as a regulatory archipelago. These come together and act in combination to regulate gene expression, with different enhancer combinations resulting in different patterns of expression. On the other hand, enhancers can act individually, with designated enhancers responsible for regulating the expression of the same gene in different tissues or at different stages of development. Indeed, this is the case for the Sonic Hedgehog gene (Shh) where several different enhancers located within a gene sparse region referred to as a gene desert, act separately leading to Shh expression in areas such as the brain, the lungs, the notochord and neural tube and the limbs. Within the developing mouse embryo, Shh is expressed over roughly a two day period from E10 to E12 in a posterior distal region referred to as the Zone of Polarising Activity (ZPA). Ectopic expression in anterior regions has been observed in some common congenital diseases which affect the limbs, sometimes resulting in the formation of extra digits. The reason for this mis-expression is largely due to defects in the Shh limb enhancer commonly referred to as the Zone of Polarising Activity Regulatory Sequence (ZRS). Mutations within this highly conserved sequence create additional protein binding sites thus activating the enhancer in the wrong locations. The associated diseases are known collectively as the ZRS associated syndromes and can range from the less severe phenotype of preaxial polydactyly type II (characterised by an extra digit near the thumb) to the more severe Werner Mesomelic Syndrome (WMS), where patients present with a clear displacement of their tibia. The mechanism by which the ZRS functions is yet to be fully elucidated, with current studies producing conflicting data. What is known, is that the region encapsulating the Shh gene is highly compact, with both the gene and its enhancers located in a highly conserved Toplogical Associated Domain (TAD) as proven by Hi-C experiments. The boundaries of this domain are likely created by the binding of the protein CTCF to specified binding sites located at the either end of the locus. This restricts the ability of the enhancers to regulate the expression of genes outside the TAD. To study the exact mechanism by which the ZRS is activated and regulates Shh expression, the Hill laboratory has used cultured cell lines derived from the posterior regions of an E11.5 limb bud. Gene expression in these cells is highly reflective of the posterior limb bud, with the key exception being Shh, which is not expressed. However, using different drug treatments or biological manipulations Shh can be activated thereby making this the perfect system to analyse the mechanisms leading to Shh activation. In this investigation the cell lines were used to determine how the position of the ZRS changes upon activation. Using techniques such as Fluorescent in situ hybridisation (FISH) with either fosmid probes or directly labelled probes called MYtags, it was confirmed that the Shh locus is indeed highly compact in both Shh expressing and non-expressing cells. However, no differences were observed in terms of the distance between the ZRS and Shh between these two conditions in our cell lines. Next, both carbon copy chromosome conformation capture (5C) and circular chromosome conformation capture (4C) were used to look at changes to the Shh locus in different conditions. This confirmed Hi-C experiments and other recent publications suggesting that Shh is located within a TAD, the position of which is highly conserved between different conditions and cell lines. Furthermore, treatments activating the Shh gene resulted in significant deviations to the chromatin interactions within the locus suggesting a repositioning of structures when the gene is active. It is believed that the use of Shh inducible limb derived cell lines will prove extremely useful in future scientific endeavours to study the mechanisms of mammalian limb development. These provide a quick and easy means of accessing large numbers of Shh expressing cells, a feature which is increasingly important in an era where large cell numbers are needed for conducting chromosome conformation capture experiments such as Hi-C, 5C and 4C.
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Spatial referentiality and openness : a portfolio of environmental sound compositionsPatrício, Eduardo Luis Brito January 2016 (has links)
Through a creative portfolio and an analytical and critical commentary, this research investigates the use of spatial references in the composition of semi-open environmental sound works. The portfolio explores a number of strategies to make use of spatial references as formal compositional components to enable more intuitive performance/reading experiences. The pieces present a number of electronically mediated scenarios in varied formats; concert, installation and mobile application. Counting on the intuitive way one tries to constantly identify surrounding spaces, each piece uses physical (performance/presentation spaces) and representational devices (illustrations, maps, video projections, spatialised sound etc.) to articulate and delimitate semi-open artistic experiences. Such ambiguous scenarios are enabled by both the unpredictability of elements of each work and the dependence on the subjective interpretations of the agents involved in the process. The creative processes presented here in a descriptive, analytical and critical manner attempt to make an artistic contribution and provide documental material for future reflection about related practices.
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Identification of Sox8 and Ndp as Novel Targets of the Hedgehog Signaling Pathway in the RetinaMcNeill, Brian 19 March 2012 (has links)
During embryonic development, the Hedgehog (Hh) signaling pathway plays an
important role in the growth and patterning of numerous tissues and organs. In the
developing retina, Hh signaling regulates the proliferation and differentiation of retinal
progenitor cells (RPC) through mechanisms that are not completely understood. The
principal downstream mediators of the Hh pathway are the Gli transcription factors (Gli1-3),
which regulate the expression of target genes responsible for the effects of the Hh pathway
on RPC. The network of genes targeted by this pathway in neural progenitor cells however,
remains unknown. The objective of this thesis was to identify and characterize novel targets
of Hh/Gli during retinal development. Using a computation approach, 390 genes were
identified as having at least one conserved Gli binding motif within the vicinity of the coding
sequence between humans and mice. During validation, I demonstrate that 30 of 46 selected
targets were modulated in response to Hh pathway activation in either E14.5 and/or P0.5
retinal explants and that the induction of 25 of these were significantly different between the
two developmental stages. Included in this list of Hh-modulated genes were Sox8 and Ndp,
two highly inducible genes that are direct targets of Gli2. Functionally, I was unable to
determine a role for Sox8 during retinal development which could reflect compensation by
the closely related Sox9 and Sox10 genes. Ndp on the other hand was found to be sufficient
and required for Hh mediated induction in progenitor cell proliferation and cell fate
determination. Therefore, in this thesis Hh target genes have been identified which could
provide some insight into the mechanisms that are responsible for the cellular outcome of a
response to the pathway.
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Phylogeny of Pempheridae inferred from sound-producing structure and DNA sequencesJiang, Yu-xuan 19 August 2010 (has links)
According to previous morphological studies on percoid phylogenies, Pempheridae may have a closer relationship to Glaucosomatidae, Teraponidae, Bramidae, Carangidae, Centropomidae, Kyphosidae, Leiognathidae, Menidae, Nandidae, Percichthyidae, Polynemidae, Sciaenidae or Toxotidae. About 10% of 515 fish families are soniferous and Pempheridae is one of the soniferous families in Percoidei. A pair of slits has been found at the anterodorsal sides of the swimbladder in Glaucosomatidae, Teraponidae and Pempheridae, and it suggests that they have closer relationship. And preliminary study on molecular phylogeny has evidence supporting that Glaucosomatidae and Pempheridae are sister goups. In this study, I compared the sonic muscle, swimbladder morphology, slit and associated structures in percoid soniferous fishes, including Pempheridae, Glaucosomatidae, Teraponidae, Sciaenidae, Priacanthidae, Haemulidae, Cichlidae and Pomacentridae. I found that there are synapomorphic characters in Pempheridae, Glaucosomatidae and Teraponidae; the slits and elastic tissue in the swimbladder are similar, and are limited to these three families. Furthermore, 16S rRNA, COI, Cytb and Rhodopsin gene sequences data were used for phylogenetic studies. And the results reveal that Pempheridae and Glaucosomatidae are sister groups and they are not closely related to Teraponidae. Therefore, the similary of sonic system in Teraponidae, Pempheridae and Glaucosomatidae may have evolved at least twice in the Percoidei and convergent evolution might also have taken placed.
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No-matter : theories and practices of the ephemeral in architectureKarandinou, Anastasia January 2011 (has links)
The architectural theorist and practitioner Bernard Tschumi asserts that enquiring and working at the limits of a discipline expands our knowledge and experience. Within this thesis I examine the limits of architecture as they relate to the non-material and the nonvisible elements of space. As Mark Wigley observes in his essay on atmosphere, architects, at different times, have sought to understand, capture and control the otherwise ungraspable aspects of space. The elusive nature of such ephemeral architectural aspects and elements makes them hard to manage and map. Their examination provides a challenging exercise within architectural research. Atmosphere is such an elusive element; as Zizek would call it, it is that which remains always as a backdrop to daily life. It seems to vanish when subjected to conscious scrutiny. Non-visual sensations such as sounds, smell, textures, temperature, clearly constitute invisible elements that are notoriously difficult to represent. As a further example, event, the way in which a space is or could be deployed or inhabited over time, provides another unpredictable and ambiguous design consideration. Spaces relate to performance. The performance of a place constitutes its nature, character, function and meaning. However, the complexity, changeability, and potentiality of spatial performance render it as something abstract and non-representable. As Steven Connor, and Jonathan Hill, amongst other theorists, observe, new media, electromagnetic fields, and digital gadgets, also constitute invisible elements of space. They create invisible fields, territories, links and boundaries, affecting everyday spaces and relationships. So a typology of the elusive and ephemeral characteristics of space would include: non-conventional materials, elements changing over time, electromagnetic fields, electronic equipment, nonvisually representable sensations, situations, processes and events. Attending closely to these themes reveals some key questions. Why do these themes appear (or re-appear) now, at this particular moment in history? How are they related to contemporary thought, practice, and to current shifts in society, culture and technological development? New technology, new means of representation, and emerging design media change both the way in which we inhabit space, and also the way in which we understand and represent it. Digital media allow us to record and represent time and duration. Hence, events and situations occurring over time can be documented and studied. Subsequently, new media can also function as a new tool to think about space, and for designing accordingly. As Marshall McLuhan claimed in the 1960s, the emergence of new digital media has caused a ‘shift in the sensorium’ and has readdressed the significance and role of experiencing and sensing other than through the visual sense. In this thesis I discuss in turn a series of limits and the qualities of the spaces that they reveal. Each chapter title is based on a binary and a theme that indicates its transgression: (a) the visual versus the non-visible – the sensuous (chapter 2), (b) the discourse about the formal versus the material – the performative (chapter 3), (c) the physical versus the digital – the hybrid (chapter 4). In order to examine these themes and explore the design potential they entail, I review relevant literature in parallel with the conduct of a series of design experiments. The experimental processes deployed are of three kinds: (1) mapping and documentation of sensory situations, (2) design experiments that challenge the issues discussed and (3) real-scale interventions that test some of the design ideas at a 1:1 scale and in an actual place. The latter includes a major installation at the 2009 Venice Biennale on the theme of Athens by Sound initiated and designed by a team involving the author.
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Identification of Sox8 and Ndp as Novel Targets of the Hedgehog Signaling Pathway in the RetinaMcNeill, Brian 19 March 2012 (has links)
During embryonic development, the Hedgehog (Hh) signaling pathway plays an
important role in the growth and patterning of numerous tissues and organs. In the
developing retina, Hh signaling regulates the proliferation and differentiation of retinal
progenitor cells (RPC) through mechanisms that are not completely understood. The
principal downstream mediators of the Hh pathway are the Gli transcription factors (Gli1-3),
which regulate the expression of target genes responsible for the effects of the Hh pathway
on RPC. The network of genes targeted by this pathway in neural progenitor cells however,
remains unknown. The objective of this thesis was to identify and characterize novel targets
of Hh/Gli during retinal development. Using a computation approach, 390 genes were
identified as having at least one conserved Gli binding motif within the vicinity of the coding
sequence between humans and mice. During validation, I demonstrate that 30 of 46 selected
targets were modulated in response to Hh pathway activation in either E14.5 and/or P0.5
retinal explants and that the induction of 25 of these were significantly different between the
two developmental stages. Included in this list of Hh-modulated genes were Sox8 and Ndp,
two highly inducible genes that are direct targets of Gli2. Functionally, I was unable to
determine a role for Sox8 during retinal development which could reflect compensation by
the closely related Sox9 and Sox10 genes. Ndp on the other hand was found to be sufficient
and required for Hh mediated induction in progenitor cell proliferation and cell fate
determination. Therefore, in this thesis Hh target genes have been identified which could
provide some insight into the mechanisms that are responsible for the cellular outcome of a
response to the pathway.
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Phonographies : practical and theoretical explorations into composing with disembodied soundDrever, John Levack January 2001 (has links)
This is PhD submission is both practical and theoretical. The practical element consists of nine electroacoustic compositions. The dissertation acts as a discursive accompaniment to the compositions, addressing many of the contextual and philosophical issues that have arisen during the compositional process and the perfannance of the works. It charts out discourse surrounding the different genres of electroacoustic music that the works relate to as well as examining models of work in the respective genres (i.e. sonic art, text, sound, acousmatic composition, inusique concrite and soundscape composition), and places them into a broader cultural and historical context. Chapter 2 is concerned with the impact of the advent of, and subsequent rapid development of electroacoustically mediatized sound on society and the individual. It relates a diverse mix of conjectures on disembodied sound from different fields, practices and cultures, including sonic art. Chapter3 explorest he emerging genre of soundscapec omposition. After dealing with the genre's lineage and accompanying discourse by composers of soundscape, it develops a relationship between the practice of soundscape composition and contemporary ethnographic practice and theory on ethnographic methodologies. The final section develops a soundscape compositional process with the practice of thefldneur. Chapter 4 relates the aesthetics of acousmatic music to philosophical, physiological and spiritual notions of the sublime throughout the ages. It concludes that acousmatic music has a distinct role to play in imparting sublime experiences. Chapter 5 documents and comments on those projects, which were undertaken with the following performers/ writers/ collaborators: Alaric Sumner, Alice Oswald and Tony Lopez. These projects demonstrate a number of different collaborative relationships between composer and writer and different configurations of acousmatic music and poetry
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