982 resultados para ancestral state reconstruction


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This paper outlines necessary and sufficient conditions for network reconstruction of linear, time-invariant systems using data from either knock-out or over-expression experiments. These structural system perturbations, which are common in biological experiments, can be formulated as unknown system inputs, allowing the network topology and dynamics to be found. We assume that only partial state measurements are available and propose an algorithm that can reconstruct the network at the level of the measured states using either time-series or steady-state data. A simulated example illustrates how the algorithm successfully reconstructs a network from data. © 2013 EUCA.

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Anisotropic gratings are recorded on bacteriorhodopsin films by two parallelly polarized beams, and the effect of the polarization orientation of the reconstructing beam on the diffraction efficiency kinetics is studied. A theoretical model for the diffraction efficiency kinetics of the anisotropic grating is developed by combining Jones-matrix and photochromic two-state theory. It is found that the polarization azimuth of the reconstructing beam produces a cosine modulation on the kinetics of the diffraction efficiency, being positive at the peak efficiency and negative for steady state. By adding auxiliary violet light during grating formation, the saturation of the grating can be restrained. As a result, the negative cosine modulation for the steady-state diffraction efficiency changes to a positive one. In addition, the steady-state diffraction efficiency is increased appreciably for all reconstructing polarization orientations. (c) 2008 Optical Society of America.

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The thermal and hydrothermal stabilities of HZSM-5 zeolites with crystal sizes less than 100 nm have been studied by multinuclear solid-state NMR, combined with BET and XRD. As evidenced by Al-27 and Si-29 MAS as well as their corresponding cross-polarization/MAS NMR investigations, the thermal stability of nanosized HZSM-5 is not so good as that of microsized HZSM-5. This is due to two processes concerning dealumination and desilicification involved in the calcination of nanosized HZSM-5, while only the dealumination process is conducted in microsized HZSM-5 under the similar calcination process. The hydrothermal stability of nanosized HZSM-5 is, contrary to what was expected, not so bad as that of the microsized HZSM-5 in the course of steam treatment. The actual resistance of the hydrothermal stability to the crystal size of HZSM-5 can be ascribed to an active reconstruction of zeolitic framework through an effective filling of amorphous Si species into nanosized HZSM-5 during hydrothermal treatment. (C) 2001 Published by Elsevier Science B.V.

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The process of making replicas of heritage has traditionally been developed by public agencies, corporations and museums and is not commonly used in schools. Currently there are technologies that allow creating cheap replicas. The new 3D reconstruction software, based on photographs and low cost 3D printers allow to make replicas at a cost much lower than traditional. This article describes the process of creating replicas of the sculpture Goslar Warrior of artist Henry Moore, located in Santa Cruz de Tenerife. To make this process, first, a digital model have been created using Autodesk Recap 360, Autodesk 123D Catch and Autodesk Meshmixer MarkerBot MakerWare applications. Physical replication, has been reproduced in polylactic acid (PLA) by MakerBot Replicator 2 3D printer. In addition, a cost analysis using, in one hand, the printer mentioned, and in the other hand, 3D printing services both online and local, is included. Finally, there has been a specific action with 141 students and 12 high school teachers, who filled a questionnary about the use of sculptural replicas in education.

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We introduce a scheme to reconstruct arbitrary states of networks composed of quantum oscillators-e. g., the motionalstate of trapped ions or the radiation state of coupled cavities. The scheme involves minimal resources and minimal access, in the sense that it (i) requires only the interaction between a one-qubit probe and a single node of the network; (ii) provides the Weyl characteristic function of the network directly from the data, avoiding any tomographic transformation; (iii) involves the tuning of only one coupling parameter. In addition, we show that a number of quantum properties can be extracted without full reconstruction of the state. The scheme can be used for probing quantum simulations of anharmonic many-body systems and quantum computations with continuous variables. Experimental implementation with trapped ions is also discussed and shown to be within reach of current technology.

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We report the experimental reconstruction of the nonequilibrium work probability distribution in a closed quantum system, and the study of the corresponding quantum fluctuation relations. The experiment uses a liquid-state nuclear magnetic resonance platform that offers full control on the preparation and dynamics of the system. Our endeavors enable the characterization of the out-of-equilibrium dynamics of a quantum spin from a finite-time thermodynamics viewpoint.

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The NeO'liberal State and the Crisis ofPublic Service Broadcasting in the Anglo-American Democracies The purpose ofthis analysis ofthe present condition ofpublic service broadcasting in the Anglo- American democracies was to investigate whether such media can still be regarded as the primarypublic spherefor a dialogue between each nation 's civil society and the State. The motivationfor this thesis was based on a presumption that such fora for public discussion on the central issues of each society have become viewed as less relevant bypoliticians andpolicy-makers and thepublics they were intended to serve in the Anglo-American democracies over thepast two decades. It is speculated that this is the case because ofa beliefthat the post-war consensus between the respective States andpublics that led to the construction of the Keynesian Welfare State and the notion ofpublic service broadcasting has been displaced by an individualistic, neo-liberal, laissez-faire ideology. In other words, broadcasting as a consumer-oriented, commercial commodity has superseded concerns pertaining to the importance ofthe public interest. The methodology employed in this thesis is a comparative analysisfrom a criticalpolitical economy perspective. It was considered appropriate to focus on the United Kingdom, Australia, Canada and the\ United States because they comprise the four largest Anglo-American nations with democratic political systems andprimarily market economies. Justificationfor this particular sample is reinforced by thefact that case study countries also share a common socio-political and economic tradition. The evidence assembledfor this thesis consisted almost exclusively ofexisting literature on the subjects ofpublic service broadcasting, global economic andpolitical integration, and the ascendance ofthe 'free-market ' ethos in Western democracies since the late mid- to late-1970s. In essence, this thesis could be considered as a reinterpretation ofthe existing literature relevant to these issues. Several important common features werefound among the political, economic and broadcasting systems of the four case study nations. It is proposed that the prevalence of the neo-liberal world view throughout the political and policy environments of the four countries has undermined the stability and credibility of each nation 's national public service broadcasting organization, although with varying intensity and effect,. Deregulation ofeach nation 's broadcasting system and the supremacy ofthe notion of 'consumer sovereignty' have marginalized the view of broadcasting on any basis other than strictly economic criteria in thefour case study countries. This thesis concludes that,for a reconstruction ofa trulyparticipatory anddemocraticpublicsphere to be realized in the present as well as thefuture, a reassessment ofthe conventional concept ofthe 'public sphere ' is necessary. Therefore, it is recommended that thefocus ofpolicy-makers in each Anglo-American democracy be redirectedfrom that which conceived ofan all-encompassing, large, state-ownedand operated public broadcasting service toward a view which considers alternativeforms ofpublic communication, such as local community and ethnic broadcasting operations, that are likely to be more responsive to the needs of the increasingly diverse and heterogeneous populations that comprise the modem Anglo-American democracies. The traditional conception of public broadcasters must change in accordance with its contemporary environment if the fundamental principles of the public sphere and public service broadcasting are to be realized.

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Please consult the paper edition of this thesis to read. It is available on the 5th Floor of the Library at Call Number: Z 9999 P65 D53 2007

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Cette thèse porte sur la reconstruction active de modèles 3D à l’aide d’une caméra et d’un projecteur. Les méthodes de reconstruction standards utilisent des motifs de lumière codée qui ont leurs forces et leurs faiblesses. Nous introduisons de nouveaux motifs basés sur la lumière non structurée afin de pallier aux manques des méthodes existantes. Les travaux présentés s’articulent autour de trois axes : la robustesse, la précision et finalement la comparaison des patrons de lumière non structurée aux autres méthodes. Les patrons de lumière non structurée se différencient en premier lieu par leur robustesse aux interréflexions et aux discontinuités de profondeur. Ils sont conçus de sorte à homogénéiser la quantité d’illumination indirecte causée par la projection sur des surfaces difficiles. En contrepartie, la mise en correspondance des images projetées et capturées est plus complexe qu’avec les méthodes dites structurées. Une méthode d’appariement probabiliste et efficace est proposée afin de résoudre ce problème. Un autre aspect important des reconstructions basées sur la lumière non structurée est la capacité de retrouver des correspondances sous-pixels, c’est-à-dire à un niveau de précision plus fin que le pixel. Nous présentons une méthode de génération de code de très grande longueur à partir des motifs de lumière non structurée. Ces codes ont l’avantage double de permettre l’extraction de correspondances plus précises tout en requérant l’utilisation de moins d’images. Cette contribution place notre méthode parmi les meilleures au niveau de la précision tout en garantissant une très bonne robustesse. Finalement, la dernière partie de cette thèse s’intéresse à la comparaison des méthodes existantes, en particulier sur la relation entre la quantité d’images projetées et la qualité de la reconstruction. Bien que certaines méthodes nécessitent un nombre constant d’images, d’autres, comme la nôtre, peuvent se contenter d’en utiliser moins aux dépens d’une qualité moindre. Nous proposons une méthode simple pour établir une correspondance optimale pouvant servir de référence à des fins de comparaison. Enfin, nous présentons des méthodes hybrides qui donnent de très bons résultats avec peu d’images.

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Les causes de la crise irakienne actuelle sont multiples. Au-delà des implications immédiates, les séquelles de l’intervention militaire de 2003 sont les plus déterminantes. L’échec du processus de reconstruction institutionnelle a donné lieu à un État déficient, dysfonctionnel et corrompu offrant ainsi un terreau fertile à l’implantation et à la prolifération des mouvements terroristes et mafieux. L’auteur tente, dans la présente contribution, d’identifier « les raisons profondes » du drame actuel en tenant compte de l’impact des bouleversements intervenus depuis la chute du régime baathiste en avril 2003 sur les structures étatiques.

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This paper examines the evolution of public rights of access to private land in England and Wales. Since the Eighteenth Century the administration and protection of these rights has been though a form of public/private partnership in which the judiciary, while maintaining the dominance of private property, have safeguarded de facto public access by refusing consistently to punish simple trespass. While this situation has been modified, principally by post-World War II legislation, to allow for some formalisation of access arrangements and consequent compensation to landowners in areas of high recreational pressure and low legal accessibility, recent policy initiatives suggest that the balance of the partnership has now shifted in favour of landowners. In particular, the new access payment schemes, developed by the UK Government in response to the European Commission's Agri-Environment Regulations, identify the landowner as the beneficiary of the partnership, financed by tax revenue and justified on the spurious basis of improved 'access provision'. As such the State, as the former upholder of citizen rights, now assumes the duplicitous position of underwriting private property ownership through the commodification of access, while proclaiming a significant improvement in citizens' access rights.

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In this study, the ovary morphology of newly emerged ant queens of Atta sexdens rubropilosa was studied in whole mount preparations by confocal microscopy. The ovaries are composed of approximately 40 ovarioles, showing non-synchronic oocyte maturation. The terminal filament with clusters of undifferentiated cells was found at the distal end of the ovarioles. Next to this region is the germarium, composed of several elongated cystocytes interconnected by cytoplasmic bridges. The nurse cells (23-28 cells) result from asymmetric mitosis. Cytoskeleton analysis showed F-actin concentrated at the muscle cells of the external tunica and in fusomes inside the ovarioles. Microtubules were concentrated around the nuclei of the nurse and follicular cells. In contrast, the oocytes and the external tunica showed faint staining for tubulin.

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In this work we employ the state-of-the-art pseudopotential method, within a generalized gradient approximation to the density functional theory, combined with a recently developed method for the calculation of HREELS spectra to study a series of different proposed models for carbon incorporation on the silicon (001) surface. A fully discussion on the geometry, energetics and specially the comparison between experimental and theoretical STM images and electron energy loss spectra indicate that the Si(100)-c(4 x 4) is probably induced by Si-C surface dinners, in agreement with recent experimental findings. (C) 2009 Elsevier B.V. All rights reserved.

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Post-war cities epitomise both a disjuncture and resonance between the end of the nation-state, on the one hand, and a preoccupation with reinventing the city through building, on the other. Programs of 'reconstruction' and 'remaking a city' are preceded by destruction: a destructive force has altered the face of the city, buildings have been destroyed and damaged, their ordered and ordering materiality is eroded, and the city is no longer an image of an idealized symbol of unity and identity. Belying the mythical power of architecture as a material and symbolic force, is also its fragility. Architecture can be monumentally erected and can have a presence and persistence that inspires awe and wonder, but it can also, just as easily be de-erected, demolished, destroyed. It can be de-constructed in a way that the literal sense of the term signals its symbolic frailty. Perceiving the symbolic as intrinsically tied to the physical articulation and presence of the architectural edifice, both reveals and conceals that the symbolic is also tied to fantasy, memory and fiction. Drawings that precede construction are projections of an idealized image of something that does not yet exist, and photographs that remain after a building is demolished are representations of a past realist that is now fictional.

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The article discusses reconstruction of East Timor in 2008 after the near-fatal shooting of President Jose Ramos-Horta and the death of his rival Major Alfredo Reinado. It notes near state collapse following the desertion of soldiers in 2006 and returning displaced persons to their homes in the aftermath.