895 resultados para Galerkin weak form


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Globalization is widely regarded as the rise of the borderless world. However in practice, true globalization points rather to a “spatial logic” by which globalization is manifested locally in the shape of insular space. Globalization in this sense is not merely about the creation of physical fragmentation of space but also the creation of social disintegration. This study tries to proof that global processes also create various forms of insular space leading also to specific social implications. In order to examine the problem this study looks at two cases: China’s Pearl River Delta (PRD) and Jakarta in Indonesia. The PRD case reveals three forms of insular space namely the modular, concealed and the hierarchical. The modular points to the form of enclosed factories where workers are vulnerable for human-right violations due to the absent of public control. The concealed refers to the production of insular space by subtle discrimination against certain social groups in urban space. And the hierarchical points to a production of insular space that is formed by an imbalanced population flow. The Jakarta case attempts to show more types of insularity in relation to the complexity of a mega-city which is shaped by a culture of exclusion. Those are dormant and hollow insularity. The dormant refers to the genesis of insular– radical – community from a culture of resistance. The last type, the hollow, points to the process of making a “pseudo community” where sense of community is not really developed as well as weak social relationship with its surrounding. Although global process creates various expressions of territorial insularization, however, this study finds that the “line of flight” is always present, where the border of insularity is crossed. The PRD’s produces vernacular modernization done by peasants which is less likely to be controlled by the politics of insularization. In Jakarta, the culture of insularization causes urban informalities that have no space, neither spatially nor socially; hence their state of ephemerality continues as a tactic of place-making. This study argues that these crossings possess the potential for reconciling venue to defuse the power of insularity.

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The motion of a viscous incompressible fluid flow in bounded domains with a smooth boundary can be described by the nonlinear Navier-Stokes equations. This description corresponds to the so-called Eulerian approach. We develop a new approximation method for the Navier-Stokes equations in both the stationary and the non-stationary case by a suitable coupling of the Eulerian and the Lagrangian representation of the flow, where the latter is defined by the trajectories of the particles of the fluid. The method leads to a sequence of uniquely determined approximate solutions with a high degree of regularity containing a convergent subsequence with limit function v such that v is a weak solution of the Navier-Stokes equations.

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Die vorliegende Arbeit berichtet über ein neuartiges, kombiniertes Messverfahren zur gleichzeitigen Erfassung von Form und Material einer glänzenden Probenoberfläche. Die Materialerkennung erfolgt über die polarisationsoptische Brechzahlbestimmung im Messpunkt mit Mikroellipsometrie. Die Mikroellipsometrie ist ein fokussierendes Ellipsometer, das aus der Polarisationsänderung, bedingt durch die Wechselwirkung Licht – Materie, die materialcharakteristische komplexe Brechzahl eines reflektierenden Materials ermitteln kann. Bei der fokussierenden Ellipsometrie ist die Anordnung der fokussierenden Optiken von Bedeutung. Die hier vorgestellte ellipsometerexterne Fokussierung vermeidet Messfehler durch optische Anisotropien und ermöglicht die multispektrale ellipsometrische Messung. Für die ellipsometrische Brechzahlbestimmung ist zwingend die Kenntnis des Einfallswinkels des Messstrahls und die räumliche Orientierung der Oberflächenneigung zum Koordinatensystem des Ellipsometers notwendig. Die Oberflächenneigung wird mit einem Deflektometer ermittelt, das speziell für den Einsatz in Kombination mit der Ellipsometrie entwickelt wurde. Aus der lokalen Oberflächenneigung kann die Topographie einer Probe rekonstruiert werden. Der Einfallswinkel ist ebenfalls aus den Oberflächenneigungen ableitbar. Die Arbeit stellt die Systemtheorie der beiden kombinierten Messverfahren vor, außerdem werden Beiträge zu Messunsicherheiten diskutiert. Der experimentelle Teil der Arbeit beinhaltet die separate Untersuchung zur Leistungsfähigkeit der beiden zu kombinierenden Messverfahren. Die experimentellen Ergebnisse erlauben die Schlussfolgerung, dass ein Mikro-Deflexions-Ellipsometer erfolgreich realisierbar ist.

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Recently Itatani et al. [Nature 432, 876 (2004)] introduced the new concept of molecular orbital tomography, where high harmonic generation (HHG) is used to image electronic wave functions. We describe an alternative reconstruction form, using momentum instead of dipole matrix elements for the electron recombination step in HHG. We show that using this velocity-form reconstruction, one obtains better results than using the original length-form reconstruction. We provide numerical evidence for our claim that one has to resort to extremely short pulses to perform the reconstruction for an orbital with arbitrary symmetry. The numerical evidence is based on the exact solution of the time-dependent Schrödinger equation for 2D model systems to simulate the experiment. Furthermore we show that in the case of cylindrically symmetric orbitals, such as the N2 orbital that was reconstructed in the original work, one can obtain the full 3D wave function and not only a 2D projection of it. Vor kurzem führten Itatani et al. [Nature 432, 876 (2004)] das Konzept der Molelkülorbital-Tomographie ein. Hierbei wird die Erzeugung hoher Harmonischer verwendet, um Bilder von elektronischen Wellenfunktionen zu gewinnen. Wir beschreiben eine alternative Form der Rekonstruktion, die auf Impuls- statt Dipol-Matrixelementen für den Rekombinationsschritt bei der Erzeugung der Harmonischen basiert. Wir zeigen, dass diese "Geschwindigkeitsform" der Rekonstruktion bessere Ergebnisse als die ursprüngliche "Längenform" liefert. Wir zeigen numerische Beweise für unsere Behauptung, dass man zu extrem kurzen Laserpulsen gehen muss, um Orbitale mit beliebiger Symmetrie zu rekonstruieren. Diese Ergebnisse basieren auf der exakten Lösung der zeitabhängigen Schrödingergleichung für 2D-Modellsysteme. Wir zeigen ferner, dass für zylindersymmetrische Orbitale wie das N2-Orbital, welches in der oben zitierten Arbeit rekonstruiert wurde, das volle 3D-Orbital rekonstruiert werden kann, nicht nur seine 2D-Projektion.

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Eukaryotic DNA m5C methyltransferases (MTases) play a major role in many epigenetic regulatory processes like genomic imprinting, X-chromosome inactivation, silencing of transposons and gene expression. Members of the two DNA m5C MTase families, Dnmt1 and Dnmt3, are relatively well studied and many details of their biological functions, biochemical properties as well as interaction partners are known. In contrast, the biological functions of the highly conserved Dnmt2 family, which appear to have non-canonical dual substrate specificity, remain enigmatic despite the efforts of many researchers. The genome of the social amoeba Dictyostelium encodes Dnmt2-homolog, the DnmA, as the only DNA m5C MTase which allowed us to study Dnmt2 function in this organism without interference by the other enzymes. The dnmA gene can be easily disrupted but the knock-out clones did not show obvious phenotypes under normal lab conditions, suggesting that the function of DnmA is not vital for the organism. It appears that the dnmA gene has a low expression profile during vegetative growth and is only 5-fold upregulated during development. Fluorescence microscopy indicated that DnmA-GFP fusions were distributed between both the nucleus and cytoplasm with some enrichment in nuclei. Interestingly, the experiments showed specific dynamics of DnmA-GFP distribution during the cell cycle. The proteins colocalized with DNA in the interphase and were mainly removed from nuclei during mitosis. DnmA functions as an active DNA m5C MTase in vivo and is responsible for weak but detectable DNA methylation of several regions in the Dictyostelium genome. Nevertheless, gel retardation assays showed only slightly higher affinity of the enzyme to dsDNA compared to ssDNA and no specificity towards various sequence contexts, although weak but detectable specificity towards AT-rich sequences was observed. This could be due to intrinsic curvature of such sequences. Furthermore, DnmA did not show denaturant-resistant covalent complexes with dsDNA in vitro, although it could form covalent adducts with ssDNA. Low binding and methyltransfer activity in vitro suggest the necessity of additional factor in DnmA function. Nevertheless, no candidates could be identified in affinity purification experiments with different tagged DnmA fusions. In this respect, it should be noted that tagged DnmA fusion preparations from Dictyostelium showed somewhat higher activity in both covalent adduct formation and methylation assays than DnmA expressed in E.coli. Thus, the presence of co-purified factors cannot be excluded. The low efficiency of complex formation by the recombinant enzyme and the failure to define interacting proteins that could be required for DNA methylation in vivo, brought up the assumption that post-translational modifications could influence target recognition and enzymatic activity. Indeed, sites of phosphorylation, methylation and acetylation were identified within the target recognition domain (TRD) of DnmA by mass spectrometry. For phosphorylation, the combination of MS data and bioinformatic analysis revealed that some of the sites could well be targets for specific kinases in vivo. Preliminary 3D modeling of DnmA protein based on homology with hDNMT2 allowed us to show that several identified phosphorylation sites located on the surface of the molecule, where they would be available for kinases. The presence of modifications almost solely within the TRD domain of DnmA could potentially modulate the mode of its interaction with the target nucleic acids. DnmA was able to form denaturant-resistant covalent intermediates with several Dictyostelium tRNAs, using as a target C38 in the anticodon loop. The formation of complexes not always correlated with the data from methylation assays, and seemed to be dependent on both sequence and structure of the tRNA substrate. The pattern, previously suggested by the Helm group for optimal methyltransferase activity of hDNMT2, appeared to contribute significantly in the formation of covalent adducts but was not the only feature of the substrate required for DnmA and hDNMT2 functions. Both enzymes required Mg2+ to form covalent complexes, which indicated that the specific structure of the target tRNA was indispensable. The dynamics of covalent adduct accumulation was different for DnmA and different tRNAs. Interestingly, the profiles of covalent adduct accumulation for different tRNAs were somewhat similar for DnmA and hDNMT2 enzymes. According to the proposed catalytic mechanism for DNA m5C MTases, the observed denaturant-resistant complexes corresponded to covalent enamine intermediates. The apparent discrepancies in the data from covalent complex formation and methylation assays may be interpreted by the possibility of alternative pathways of the catalytic mechanism, leading not to methylation but to exchange or demethylation reactions. The reversibility of enamine intermediate formation should also be considered. Curiously, native gel retardation assays showed no or little difference in binding affinities of DnmA to different RNA substrates and thus the absence of specificity in the initial enzyme binding. The meaning of the tRNA methylation as well as identification of novel RNA substrates in vivo should be the aim of further experiments.

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Among organic materials, spirobifluorene derivatives represent a very attractive class of materials for electronic devices. These compounds have high melting points, glass transitions temperatures and morphological stability, which makes these materials suitable for organic electronic applications. In addition, some of spirobifluorenes can form porous supramolecular associations with significant volumes available for the inclusion of guests. These molecular associations based on the spirobifluorenes are noteworthy because they are purely molecular analogues of zeolites and other microporous solids, with potential applications in separation, catalysis, sensing and other areas.

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In der vorliegenden Arbeit wurde die Biofilmbildung bei einem klinischen Isolat von Enterococcus faecalis untersucht. Der Prozess der Biofilmbildung ist in mehrere Abschnitte unterteilt und beinhaltet zu Beginn eine Anhaftung von Zellen an Oberflächen. Dieser adhäsive Schritt wird unter anderem durch Pili vermittelt. Pili bei Grampositiven Mikroorganismen sind kovalent mit der Zellwand verknüpfte Proteinstrukturen, die eine Anheftung an biotische und abiotische Oberflächen sowie den Zell-Zell-Kontakt vermitteln. Bei den Analysen dieser Doktorarbeit lag ein besonderes Interesse bei eben diesen Pili, die für Enterococcus faecalis die Namen Ebp (endocarditis and biofilm associated pili) und Bee (biofilm enhancer in enterococci) tragen. Codiert werden sie durch die entsprechenden ebp-/bee-Loci, deren Aufbau unter den Grampositiven Mikroorganismen hochkonserviert ist. Die Loci bestehen aus Pilusuntereinheiten-codierenden Genen und colokalisierten Pilus-spezifischen Sortase Genen. Während in der Regel drei verschiedene Pilusuntereinheiten vorliegen, kann die Anzahl der Sortasen zwischen einer und zwei variieren. Bei den Experimenten wurde neben einer Komplementationsstudie zu einer Bee-Pilus Defekt-Mutante (1.10.16) das Hauptaugenmerk auf die Analyse des zweiten Pilus (Ebp) gelegt, um die Pilisituation bei Isolat 1.10 im Detail darzustellen Zusätzlich sollten weitere Oberflächenassoziierte Proteinstrukturen bei Isolat 1.10 detektiert werden, die gegebenenfalls an der Biofilmbildung beteiligt sind. Weitere Versuche zur Charakterisierung des Bee-Pilus wurden im Laufe dieser Arbeit durchgeführt, blieben jedoch bisher erfolglos. Die Biofilm-/Pilus-Defekt-Mutante 1.10.16 zeigte aufgrund einer Punktmutation (Pm) in der Pilus-spezifischen Sortase 1 des bee-Locus eine geschwächte Fähigkeit zur Anheftung an abiotische Oberflächen, sowie das Fehlen der Bee2 Untereinheit im Pilus. Nach Komplementation der Mutante (1.10.16K) mit dem Wildtyp-srt1 Gen, wurde die starke Biofilmbildungsfähigkeit zurück erlangt. Die Experimente zeigten, dass der Pilus-Defekt auf die Pm im srt1 Gen zurückzuführen war und der Bee-Pilus in Stamm 1.10.16K wieder korrekt gebildet wurde. Zu sehen war dies in Rasterelektronenmikroskopischen Aufnahmen und ebenfalls im massenspektrometrischen Nachweis aller 3 Pilusuntereinheiten im Bee-Pilus charakteristischen High-Molecular-Weight Komplex (~ 250 kDa). Durch Sequenzierungen konnte gezeigt werden, dass zwei Gene des ebp-Locus (ebpR und ebpC) bei Isolat 1.10 durch die Insertion von IS-Elementen IS1062 und IS6770 inaktiviert wurden. Der proteinbiochemische Nachweis über Pilusspezifische Antikörper gegen die Untereinheiten des Ebp-Pilus verlief negativ. Zusätzlich konnte gezeigt werden, dass die mRNA der beiden inaktivierten Gene nicht gebildet wurde. Dies führte folglich zum vollständigen Verlust des Ebp-Pilus bei Isolat 1.10. Zusammen mit den Ergebnissen der Komplementation konnte somit der große Einfluss mindestens eines intakten Pilus auf die Biofilmbildung gezeigt werden. Sind beide Pili durch Insertionen bzw. Mutationen inaktiviert, kommt es zu einer deutlichen Abnahme der Biofilmbildungsstärke. Dass trotzdem noch ein Biofilm gebildet wurde, zeigt den multifaktoriellen Zusammenhang bzw. Einfluss im Biofilmbildungsprozess. Über das gezielte Markieren von Oberflächenproteinen intakter Zellen mittels der Oberflächenbiotinylierung, konnten in der SDS-PAGE Unterschiede im Bandenmuster im Vergleich zur unbehandelten Probe erkannt werden. Die massenspektrometrische Identifikation dieser Proteine erfolgte bisher nicht, jedoch sind diese vorläufigen Ergebnisse vielversprechender Natur für die Identifikation und Aufklärung der Oberflächenproteinsituation bei Isolat 1.10.

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For over 1,000 years, the Balinese have developed a unique system of democratic and sustainable water irrigation. It has shaped the cultural landscapes of Bali and enables local communities to manage the ecology of terraced rice fields at the scale of whole watersheds. The Subak system has made the Balinese the most productive rice growers in Indonesia and ensures a high level of food sovereignty for a dense population on the volcanic island. The Subak system provides a vibrant example of a diverse, ecologically sustainable, economically productive and democratic water management system that is also characterized by its nonreliance on fossil fuel derivatives or heavy machinery. In 2012, UNESCO has recognized five rice terraces and their water temples as World Heritage site and supports its conservation and protection. However, the fragile Subak system is threatened for its complexity and interconnectedness by new agricultural practices and increasing tourism on the island.

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El cuaderno incluye una gu??a did??ctica para el profesor

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The processes underlying the perceptual analysis of visual form are believed to have minimal interaction with those subserving the perception of visual motion (Livingstone and Hubel, 1987; Victor and Conte, 1990). Recent reports of functionally and anatomically segregated parallel streams in the primate visual cortex seem to support this hypothesis (Ungerlieder and Mishkin, 1982; VanEssen and Maunsell, 1983; Shipp and Zeki, 1985; Zeki and Shipp, 1988; De Yoe et al., 1994). Here we present perceptual evidence that is at odds with this view and instead suggests strong symmetric interactions between the form and motion processes. In one direction, we show that the introduction of specific static figural elements, say 'F', in a simple motion sequence biases an observer to perceive a particular motion field, say 'M'. In the reverse direction, the imposition of the same motion field 'M' on the original sequence leads the observer to perceive illusory static figural elements 'F'. A specific implication of these findings concerns the possible existence of (what we call) motion end-stopped units in the primate visual system. Such units might constitute part of a mechanism for signalling subjective occluding contours based on motion-field discontinuities.

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In the eighties, John Aitchison (1986) developed a new methodological approach for the statistical analysis of compositional data. This new methodology was implemented in Basic routines grouped under the name CODA and later NEWCODA inMatlab (Aitchison, 1997). After that, several other authors have published extensions to this methodology: Marín-Fernández and others (2000), Barceló-Vidal and others (2001), Pawlowsky-Glahn and Egozcue (2001, 2002) and Egozcue and others (2003). (...)

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Resumen tomado de la publicaci??n

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This is the full Module Evaluation Form adopted by the University of Southampton. The latest editable file can be downloaded from the Learning and Teaching Enhancement Unit (LATEU) of the University. Included in this resource is the online version of the form for use in Blackboard, WebCT and other virtual learning environments. If you are using Blackboard, you are advised to use Internet Explorer version 6 or higher. Save the Blackboard zip archive to a local drive. Do not rename the file name. Go to the destination course area in Blackboard, open the "Control Panel" and then start the "Survey Manager" (in the "Assessment" group). Use the "Import" command to upload the zip archive. Once this is completed, rename the evaluation form which can then be added to any content area within the course using the dropdown "Add Survey" command.

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IMAGINING LTDA, es una empresa de publicidad, que decide aventurarse en un plan de reestructuración antes de ver el cierre como una posible opción. En ese sentido se empieza un total plan donde prácticamente se desarma lo poco que había en la empresa y se empieza de cero. El principal resultado es que se logra desarrollar un modelo de negocio planteado como “Agencia de Publicidad Express”, que logra integrar una serie de componentes estratégicos, que separados son diferenciales muy débiles, pero juntos se integran y se convierten en un gran diferencial estratégico generador de ventaja competitiva. Haciendo un estudio profundo, de la industria, el sector y la demanda, se puede ver que es un campo muy competido y hacinado sobretodo, sin embargo existen algunas necesidades en canal y cliente muy fuertes, que permiten desarrollar un modelo diferente en publicidad, que es en lo que IMAGINING, decide enfocarse para ser diferente y atacar exclusivamente como agencia a las empresas denominadas como “PYME”. Todo esto resulta enfocándose en un sistema organizacional que permite una eficiencia y una concentración de decisiones que le permite a la empresa ir consolidándose con la rapidez que el cliente necesita y que solo IMAGINING puede ofrecer. El enfoque de mercado, por supuesto gira en base a las 4 P’s del mercadeo, que diferencian un producto que se hace a través de los estándares de calidad y la forma como se va a promocionar y vender ante las personas, con una política de precios lo suficientemente competitiva y accesible para el mercado que se aspira conquistar. De ahí se deriva un concepto de vender publicidad fácil y objetivamente sin que haya diferencias de uno a otro cliente. Financieramente el modelo resulta ser muy atractivo, y vendiendo relativamente poco se pueden recuperar márgenes de inversión muy altos puesto que la utilidad es muy alta en el negocio y más cuando no se sub contratan las cosas sino se quiere hacer todo directamente como lo hace IMAGINING.

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