867 resultados para Dislocation Patterning


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This chapter examines the poetry of Scottish South Asians, the "New Scots" who bring a whole history of displacement, dislocation and relocation with them, as their memory of the "elsewhere" enters their writing. Their voices are significant as they embody multicultural Scotland with postcolonial dialects that signify an encounter in the Third Space where they are affected by and affect the "host" community. This chapter will question whether the writing of "New Scots" has added more than just "colour" to Scottish Poetry, as it traces the recent migrant history and analyses the lives and "voices" of diasporic communities as evident in their poetry. The objective is to assess how the new "voices" have blended in, expanded and/or challenged the boundaries of what defines Scottish Poetry, and determine whether they form a "community" of poets distinguished by the complexity of their regional allegiances, both past and present.

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The railroad, from 1870 and on, becomes an usual complaining in the press s and politician elite s speeches, especially because of Natal s geographic isolation. The implantation of two railroads in the capital territory Estrada de Ferro de Natal a Nova Cruz, afterwards part of Great Western Railway Company network, and Estrada de Ferro Central do Rio Grande do Norte had serious implications in the urban environment. While railroad s structures were already consolidated, other transportation mechanisms were being implanted in the first decades of the 20th century, such as trams lines, which, by the way, was a transport modal that also used rails as a dislocation meaning. Considering these questions, we may ask: how come railroads and tramways demands, roads and buildings had influenced the internal organization of Natal? We work with the general hypothesis that the influence of technical networks, composed by tramways and railroads, over Natal s urban space happened in a diversified way, sometimes consolidating social aspects in certain areas, sometimes improving the occupation of others. The impact over the city s territory also happens in a diversified way between the buildings/railroad s complexes and the pathways. The different scale of the train in comparison to the trams velocity, size, noise level, flow, among others is also a cause to the different consequences in urban environment. The main objective of this work is to understand the role of circulation technical networks in the construction process of urban space in Natal, as a way to contribute to the urban historiography about the subject. The time frame adopted, between 1881 and 1937, marks the time path of railroads and tramways in Rio Grande do Norte: 1881 is the year of railroad s first section inauguration from Natal to São José do Mipibu as well of the railroad complex in the Republic Square in Natal; the year of 1937 marks the beginning of tramways declination process in the city. At this time railroads and tramways had to face more intensively the competition of motor vehicles. The theory reference adopted is based on concepts and analysis of authors, such as Flávio Villaça and Roberto Lobato Corrêa references to the concepts of urban structure , localization and accessibility and Gabriel Dupuy to explain the concept of urban technical networks . These references reveal the conflict of different realities in the urban universe interests and values which is an important factor about the construction of urban space. The information sources used were from two distinctive natures: primary, journals of the time studied and official government reports, and secondary, based on other works about the subject. It was also used by this study iconographic source, especially images from the data base of the research group História da Cidade, do Território e do Urbanismo .

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The object of this article is to offer a synthesis of the knowledge clarifying the originality and the diversity of the submarine geological formations of the New Caledonian EEZ. A reminder is given onto the geologic history of the region, based upon the dislocation of the Gondwana Continent, the opening of the Tasman Sea, the presence of submarine volcanism, the setting up of heavy peridotitic rocks, the building up of the Fairway and Lord Howe Ridges and of sedimentary basins, the formation of volcanic domes and sea-mounts or guyots, the subduction along the Vanuatu Trench, the uplift of the Loyalty Islands, the development of carbonated ptatforms around the islands etc.... Of this complex history ensues an exceptional submarine geo-diversity. After this presentation the article clarifies the methods and the tools used in marine geosciences to map, explore, observe, analyze, sample, that they are embarked or are autonomous, teleoperated or inhabited systems. A chapter describes the programs which were set up since about forty years and the results obtained as well as the scientific teams concerned with. In conclusion, based on the unpublished character of this geo-diversity, the article introduces the second text to come in a next issue of theTai Kona magazine, text which will focus on the scientific, economic (mineral resources), environmental (deep biodiversity) and risks (seismicity) challenges that are worn by one of the most original submarine geologic context in the world.

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Proper organ patterning depends on a tight coordination between cell proliferation and differentiation. The patterning of Drosophila retina occurs both very fast and with high precision. This process is driven by the dynamic changes in signaling activity of the conserved Hedgehog (Hh) pathway, which coordinates cell fate determination, cell cycle and tissue morphogenesis. Here we show that during Drosophila retinogenesis, the retinal determination gene dachshund (dac) is not only a target of the Hh signaling pathway, but is also a modulator of its activity. Using developmental genetics techniques, we demonstrate that dac enhances Hh signaling by promoting the accumulation of the Gli transcription factor Cubitus interruptus (Ci) parallel to or downstream of fused. In the absence of dac, all Hh-mediated events associated to the morphogenetic furrow are delayed. One of the consequences is that, posterior to the furrow, dac- cells cannot activate a Roadkill-Cullin3 negative feedback loop that attenuates Hh signaling and which is necessary for retinal cells to continue normal differentiation. Therefore, dac is part of an essential positive feedback loop in the Hh pathway, guaranteeing the speed and the accuracy of Drosophila retinogenesis.

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During early vertebrate development, the correct establishment of the body axes is critical. The anterior pole of the mouse embryo is established when Distal Visceral Endoderm (DVE) cells migrate to form the Anterior Visceral Endoderm (AVE). Symmetrical expression of Lefty1, Cer1 and Dkk1 determines the direction of DVE migration and the future anterior side. In addition to the establishment of the Anterior-Posterior axis, the AVE has also been implicated in anterior neural specification. To better understand the role of the AVE in these processes, we have performed a differential screening using Affymetrix GeneChip technology with AVE cells isolated from cer1P-EGFP transgenic mouse embryos. We found 175 genes which were upregulated in the AVE and 36 genes in the Proximal-posterior sample. Using DAVID software, we characterized the AVE cell population regarding cellular component, molecular function and biological processes. Among the genes that were found to be upregulated in the AVE, several novel genes were identified. Four of these transcripts displaying high-fold change in the AVE were further characterized by in situ hybridization in early stages of development in order to validate the screening. From those four selected genes, one, denominated Adtk1, was chosen to be functionally characterized by targeted inactivation in ES cells. Adtk1 encodes for a serine/threonine kinase. Adtk1 null mutants are smaller and present short limbs due to decreased mineralization, suggesting a potential role in chondrogenesis during limb development. Taken together, these data point to the importance of reporting novel genes present in the AVE.

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The first part of the thesis describes a new patterning technique--microfluidic contact printing--that combines several of the desirable aspects of microcontact printing and microfluidic patterning and addresses some of their important limitations through the integration of a track-etched polycarbonate (PCTE) membrane. Using this technique, biomolecules (e.g., peptides, polysaccharides, and proteins) were printed in high fidelity on a receptor modified polyacrylamide hydrogel substrate. The patterns obtained can be controlled through modifications of channel design and secondary programming via selective membrane wetting. The protocols support the printing of multiple reagents without registration steps and fast recycle times. The second part describes a non-enzymatic, isothermal method to discriminate single nucleotide polymorphisms (SNPs). SNP discrimination using alkaline dehybridization has long been neglected because the pH range in which thermodynamic discrimination can be done is quite narrow. We found, however, that SNPs can be discriminated by the kinetic differences exhibited in the dehybridization of PM and MM DNA duplexes in an alkaline solution using fluorescence microscopy. We combined this method with multifunctional encoded hydrogel particle array (fabricated by stop-flow lithography) to achieve fast kinetics and high versatility. This approach may serve as an effective alternative to temperature-based method for analyzing unamplified genomic DNA in point-of-care diagnostic.

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Based on the presupposition that the arts in the West always counted on resources, supports, and devices pertaining to its time context, an reflection is intended regarding the scenic compositions mediated by digital technologies do. Such technologies are inserted in the daily routine, also composing artistic experiments, thus playing a dialogical role with the art/technology intersection. Therefore, the proposal is to investigate what relationships are established in the contemporary theatrical scene from the contagion by digital technologies, aiming at establishing this parallel through a dialogue with the authors discussing the subject, and also based on the group practices having technological resources as a determinant factor in their plays. Furthermore, a reflection should be made on the scene that incorporates or is carried out in intermediatic events, analyzing how digital technologies (re)configure compositional processes of the plays by GAG Phila7, in the city of São Paulo/SP. For such, the dissertation is organized in three sections comprising four moments, to wit: brief overview of the field, contextualization, poetic analysis and synthesis. Qualitative methods are used as the methodological proposal: semi-structure interview, note and document taking (program, website, playing book, disclosure material for advertising text, photographs, and videos). Within the universe of qualitative research, it works with the epistemological perspective of the Gadamer philosophical hermeneutics. The possibilities allowed by the double virtual (Internet/web) generated a type of theater with another material basis and new forms of organization and structure, being possible to perceive that such technological advances and the arts are mutually contaminated, generating a dislocation in the logics of theatrical composition, movement beginning with the artistic vanguards, gradually intensified, thus offering new possibilities of constructions and hybridization of the of the most different possible types. Experiment ―Profanações_superfície de eventos de construção coletiva‖, idealized by Phila7 is inserted in this perspective. Object of the discussion of such research, the experiment works with possible poetics arising from the intersection with the digital technologies, aiming at identifying and problematizing the challenges from the technological evolution and expansion in a scenic context

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Frustrated systems, typically characterized by competing interactions that cannot all be simultaneously satisfied, are ubiquitous in nature and display many rich phenomena and novel physics. Artificial spin ices (ASIs), arrays of lithographically patterned Ising-like single-domain magnetic nanostructures, are highly tunable systems that have proven to be a novel method for studying the effects of frustration and associated properties. The strength and nature of the frustrated interactions between individual magnets are readily tuned by design and the exact microstate of the system can be determined by a variety of characterization techniques. Recently, thermal activation of ASI systems has been demonstrated, introducing the spontaneous reversal of individual magnets and allowing for new explorations of novel phase transitions and phenomena using these systems. In this work, we introduce a new, robust material with favorable magnetic properties for studying thermally active ASI and use it to investigate a variety of ASI geometries. We reproduce previously reported perfect ground-state ordering in the square geometry and present studies of the kagome lattice showing the highest yet degree of ordering observed in this fully frustrated system. We consider theoretical predictions of long-range order in ASI and use both our experimental studies and kinetic Monte Carlo simulations to evaluate these predictions. Next, we introduce controlled topological defects into our square ASI samples and observe a new, extended frustration effect of the system. When we introduce a dislocation into the lattice, we still see large domains of ground-state order, but, in every sample, a domain wall containing higher energy spin arrangements originates from the dislocation, resolving a discontinuity in the ground-state order parameter. Locally, the magnets are unfrustrated, but frustration of the lattice persists due to its topology. We demonstrate the first direct imaging of spin configurations resulting from topological frustration in any system and make predictions on how dislocations could affect properties in numerous materials systems.

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The function of a complex nervous system relies on an intricate interaction between neurons and glial cells. However, as glial cells are generally born distant from the place where they settle, molecular cues are important to direct their migration. Glial cell migration is important in both normal development and disease, thus current research in the laboratory has been focused on dissecting regulatory events underlying that crucial process. With this purpose, the Drosophila eye imaginal disc has been used as a model. In response to neuronal photoreceptor differentiation, glial cells migrate from the CNS into the eye disc where they act to correctly wrap axons. To ensure proper development, attractive and repulsive signals must coordinate glial cell migration. Importantly, one of these signals is Bnl, a Fibroblast Growth Factor (FGF) ligand expressed by retinal progenitor cells that was suggested to act as a non-autonomous negative regulator of excessive glial cell migration (overmigration) by binding and activating the Btl receptor expressed by glial cells. Through the experimental results described in chapter 3 we gained a detailed insight into the function of bnl in eye disc growth, photoreceptor development, and glia migration. Interestingly, we did not find a direct correlation between the defects on the ongoing photoreceptors and the glia overmigration phenotype; however, bnl knockdown caused apoptosis of eye progenitor cells what was strongly correlated with glia migration defects. Glia overmigration due to Bnl down-regulation in eye progenitor cells was rescued by inhibiting the pro-apoptotic genes or caspases activity, as well as, by depleting JNK or Dp53 function in retinal progenitor cells. Thus, we suggest a cross-talk between those developmental signals in the control of glia migration at a distance. Importantly, these results suggest that Bnl does not control glial migration in the eye disc exclusively through its ability to bind and activate its receptor Btl in glial cells. We also discuss possible biological roles for the glia overmigration in the bnl knockdown background. Previous results in the lab showed an interaction between dMyc, a master regulator of tissue growth, and Dpp, a Transforming Growth Factor-β important for retinal patterning and for accurate glia migration into the eye disc. Thus, we became interested in understanding putative relationships between Bnl and dMyc. In chapter 4, we show that they positively cooperate in order to ensure proper development of the eye disc. This work highlights the importance of the FGF signaling in eye disc development and reveals a signaling network where a range of extra- and intra-cellular signals cooperate to non-autonomously control glial cell migration. Therefore, such inter-relations could be important in other Drosophila cellular contexts, as well as in vertebrate tissue development.

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The main theme of this thesis is the social, economic and political response of a single community to economic dislocation in the interwar years. The community under consideration is Clydebank., The thesis is divided into several parts. Part I establishes the development of the burgh and considers the physical framework of the community, mainly in the years before 1919. The town's characteristics are examined in terms of population structure and development between the world wars. In the last part of this section there is a review of the economic structure of the burgh and changes occurring in it between 1919 and 1939. In Part II consideration is given to the actual extent and form of the unemployment affecting Clydebank at this time, and comparison is made with other communities and geographic/economic areas. Attention is then focussed more narrowly on the actual individuals suffering unemployment in the burgh during the 1930s, in an attempt to personalise the experience of the unemployed. Part III reviews central and local government responses to the situation in which Clydebank found itself oetween 1919 and 1939. Central government policies discussed include unemployment insurance, public works, the Special Areas legislation, assistance in the construction of the 534 "Queen Mary" and the direction of financial support to areas of particular need. Amongst local authority actions described are additional local support for the poor, public works, efforts to attract new industry to the town, attempts to deal with the housing problem which was particularly acute at times of high unemployment and measures to maintain health standards in the community. In Part IV the responses of the community to unemployment and government policies are detailed. The burgh's commercial sector is surveyed as are developments in leisure provision, religion, temperance and crime, and local politics. A number of individual responses are also given consideration such as migration, commuting, changes in birth and marriage rates and suicide.

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The surge of interest in graphene, as epitomized by the Nobel Prize in Physics in 2010, is attributed to its extraordinary properties. Graphene is ultrathin, mechanically tough, and has amendable surface chemistry. These features make graphene and graphene based nanostructure an ideal candidate for the use of molecular mass manipulation. The controllable and programmable molecular mass manipulation is crucial in enabling future graphene based applications, however is challenging to achieve. This dissertation studies several aspects in molecular mass manipulation including mass transportation, patterning and storage. For molecular mass transportation, two methods based on carbon nanoscroll are demonstrated to be effective. They are torsional buckling instability assisted transportation and surface energy induced radial shrinkage. To achieve a more controllable transportation, a fundamental law of direction transport of molecular mass by straining basal graphene is studied. For molecular mass patterning, we reveal a barrier effect of line defects in graphene, which can enable molecular confining and patterning in a domain of desirable geometry. Such a strategy makes controllable patterning feasible for various types of molecules. For molecular mass storage, we propose a novel partially hydrogenated bilayer graphene structure which has large capacity for mass uptake. Also the mass release can be achieved by simply stretching the structure. Therefore the mass uptake and release is reversible. This kind of structure is crucial in enabling hydrogen fuel based technology. Lastly, spontaneous nanofluidic channel formation enabled by patterned hydrogenation is studied. This novel strategy enables programmable channel formation with pre-defined complex geometry.

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Cellular behavior is dependent on a variety of extracellular cues required for normal tissue function, wound healing, and activation of the immune system. Removed from their in vivo microenvironment and cultured in vitro, cells lose many environmental cues and that may result in abberant behavior, making it difficult to study cellular processes. In order to mimic native tissue environments, optical tweezer and microfluidic technologies were used to place cells within defined areas of the culture environment. To provide three dimensional supports found in natural tissues, hydrogel scaffolds of poly (ethylene glycol) diacrylate and the basement membrane matrix Matrigel were used. Optical tweezer technology allowed precision placement and formation of homotypic and heterotypic arrays of human U937, HEK 293, and porcine mesenchymal stem cells. Alternatively, two microfluidic devices were designed to pattern Matrigel scaffolds. The first microfluidic device utilized laminar flow to spatially pattern multiple cell types within the device. Gradients of soluble molecules were then be formed and manipulated across the Matrigel scaffolds. Patterning Matrigel using laminar flow techniques require microfluidic expertise and do not produce consistent patterning conditions, limiting their use difficult in most cell culture laboratories. Thus, a buried Matrigel polydimethylsiloxane (PDMS) device was developed for spatial patterning of biological scaffolds. Matrigel is injected into micron sized channels of PDMS fabricated by soft lithography and allowed to thermally cure. Following curing, a second PDMS device was placed on top of the buried Matrigel channels to support media flow. In order to validate these systems, a cell-cell communication model system was developed utilizing LPS and TNFα signaling with fluorescent reporter systems to monitor communication in real time. We demonstrated the utility of microfluidic devices to support the cell-cell communication model system by co culturing three cell types within Matrigel scaffolds and monitoring signaling activity via fluorescent reporters.