87 resultados para Twin Paradox


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Chapters 3 and 15 of Joyce's Ulysses exhibit glimpses of three dreams, fantasies and eventual nightmares linked to the figure of 'Haroun al Raschid.' Historically speaking, the latter was a powerful Caliph of Baghdad, a medieval potentate about whom many of the most memorable of The Thousand and One Nights or The Arabian Nights' Entertainments were once and then again spun as tales of pleasure. Joyce seizes upon the figure of 'Haroun al Raschid' as a fictive measure to articulate the 'orientalist' fantasies of Stephen Dedalus and Leopold Bloom. However, this evocative figure of Near Eastern history, of fabulous narrative and the progressively converging fantasies of two modern European literary characters is riddled with paradox. Such material provides Joyce a perceptive and proleptic sense of the paradoxes and brutal historical contradictions through which Western and Eastern dreams of theocratic nationalism, ethnic zealotry, colonial rebellion and Zionism are to be played out. W. B. Yeats' poem 'The Gift of Harun al-Raschid', written in 1923, the year after the book publication of Ulysses, provides both a fitting foil and a significant socio-historical point of reference for Joyce's own figurative use of the Caliph of Baghdad.

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Using patch-clamp and calcium imaging techniques, we characterized the effects of ATP and histamine on human keratinocytes. In the HaCaT cell line, both receptor agonists induced a transient elevation of [Ca2+]i in a Ca2+-free medium followed by a secondary [Ca2+]i rise upon Ca2+ readmission due to store-operated calcium entry (SOCE). In voltage-clamped cells, agonists activated two kinetically distinct currents, which showed differing voltage dependences and were identified as Ca2+-activated (ICl(Ca)) and volume-regulated (ICl, swell) chloride currents. NPPB and DIDS more efficiently inhibited ICl(Ca) and ICl, swell, respectively. Cell swelling caused by hypotonic solution invariably activated ICl, swell while regulatory volume decrease occurred in intact cells, as was found in flow cytometry experiments. The PLC inhibitor U-73122 blocked both agonist- and cell swelling–induced ICl, swell, while its inactive analogue U-73343 had no effect. ICl(Ca) could be activated by cytoplasmic calcium increase due to thapsigargin (TG)-induced SOCE as well as by buffering [Ca2+]i in the pipette solution at 500 nM. In contrast, ICl, swell could be directly activated by 1-oleoyl-2-acetyl-sn-glycerol (OAG), a cell-permeable DAG analogue, but neither by InsP3 infusion nor by the cytoplasmic calcium increase. PKC also had no role in its regulation. Agonists, OAG, and cell swelling induced ICl, swell in a nonadditive manner, suggesting their convergence on a common pathway. ICl, swell and ICl(Ca) showed only a limited overlap (i.e., simultaneous activation), although various maneuvers were able to induce these currents sequentially in the same cell. TG-induced SOCE strongly potentiated ICl(Ca), but abolished ICl, swell, thereby providing a clue for this paradox. Thus, we have established for the first time using a keratinocyte model that ICl, swell can be physiologically activated under isotonic conditions by receptors coupled to the phosphoinositide pathway. These results also suggest a novel function for SOCE, which can operate as a "selection" switch between closely localized channels.

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This article compares the processes of foreign policymaking in Greece and Turkey in order to examine why the incentives and pressures of the enlargement process have failed until now to initiate a settlement in the Cyprus bicommunal negotiations. While most studies on the Cyprus problem have focused on the two communities of the island, little at-tention has been paid to the policies of the two â??motherlandsâ??, namely Greece and Turkey. Yet their leverage on the two Cypriot communities and their conflicting expectations with regard to an enlarged Europe in the Eastern Mediterranean constitute a complex security puzzle. The Republic of Cyprus stands as a champion candidate member for the next enlargement, amid fears of Turkish reprisals and hopes for a po-litical settlement on the island. With the benefits of settlement overwhelming the benefits of any other alternative, it is paradoxical that the parties seem to be about to fail to reach a last-minute, mutually beneficial compromise. I try to resolve this paradox by supplementing rational choice theory with cognitivist theories of international relations. While rational choice predicts a direct relationship between external environment and foreign policy shifts, the case of Cyprus suggests that this relationship is actually indirect. Without understanding how the external environment is framed in the domestic political discourse of Greece and Turkey, it is impossible to demonstrate how outside pressure and incentives affect foreign policy shifts.

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We exploit the analogy between the transfer of a pulse across a scattering medium and Aharonov's weak measurements to resolve the long standing paradox between the impossibility to exceed the speed of light and the seemingly "superluminal" behavior of a tunneling particle in the barrier or a photon in a "fast-light" medium. We demonstrate that superluminality occurs when the value of the duration tau spent in the barrier is uncertain, whereas when tau is known accurately, no superluminal behavior is observed. In all cases only subluminal durations contribute to the transmission which precludes faster-than-light information transfer, as observed in a recent experiment.

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This article considers the paradox of improvisation as a gift out of time, which is completely in tune with time, subject to time. It does so through an alignment of Jacques Derrida’s philosophy and the poetic writings of Hélène Cixous. Ever mindful of the possible impossibility of improvisation in Derrida’s work, improvisation here is given over to Cixous, to the side of life, and is theorised as a type of ‘feminine writing’, as an inventive strategy that calls forth the unknown other and dreams of a gift in life that is out of time.

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We propose an experimentally feasible scheme to generate a superposition of travelling field coherent states using an extremely small Kerr effect and an ancilla which could be a single photon or two entangled twin photons. The scheme contains ingredients which are all within the current state of the art and is robust against the main sources of errors which can be identified in our setups.

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We employ a quantum mechanical bond order potential in an atomistic simulation of channeled flow. We show that the original hypothesis that this is achieved by a cooperative deployment of slip and twinning is correct, first because a twin is able to “protect” a 60° ordinary dislocation from becoming sessile, and second because the two processes are found to be activated by Peierls stresses of similar magnitude. In addition we show an explicit demonstration of the lateral growth of a twin, again at a similar level of stress. Thus these simultaneous processes are shown to be capable of channeling deformation into the observed state of plane strain in so-called “A”-oriented mechanical testing of titanium aluminide superalloy.

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Composites of poly(e-caprolactone) (PCL) and molybdenum sulfur iodine (MoSI) nanowires were prepared using twin-screw extrusion. Extensive microscopic examination of the composites revealed the nanowires were well dispersed in the PCL matrix, although bundles of Mo6S3I6 ropes were evident at higher loadings. Secondary electron imaging (SEI) showed the nanowires had formed an extensive network throughout the PCL matrix, resulting in increased electrical conductivity of PCL, by eight orders of magnitude, and an electrical percolation threshold of 6.5T10S3vol%. Thermal analysis (DSC), WAXD, and hot stage polarized optical microscopy (HSPOM) experiments revealed Mo6S3I6 addition altered PCL crystallization kinetics, nucleation density, and crystalline content. A greater number of smaller spherulites were formed via heterogeneous nucleation. The onset of thermal decomposition (TGA) of PCL decreased by 70-C, a consequence of the thermal degradation of Mo6S3I6 to MoO3, which in turn accelerates the formation of volatile gases during the first stage of PCL decomposition.

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Hunter and Konieczny explored the relationships between measures of inconsistency for a belief base and the minimal inconsistent subsets of that belief base in several of their papers. In particular, an inconsistency value termed MIVC, defined from minimal inconsistent subsets, can be considered as a Shapley Inconsistency Value. Moreover, it can be axiomatized completely in terms of five simple axioms. MinInc, one of the five axioms, states that each minimal inconsistent set has the same amount of conflict. However, it conflicts with the intuition illustrated by the lottery paradox, which states that as the size of a minimal inconsistent belief base increases, the degree of inconsistency of that belief base becomes smaller. To address this, we present two kinds of revised inconsistency measures for a belief base from its minimal inconsistent subsets. Each of these measures considers the size of each minimal inconsistent subset as well as the number of minimal inconsistent subsets of a belief base. More specifically, we first present a vectorial measure to capture the inconsistency for a belief base, which is more discriminative than MIVC. Then we present a family of weighted inconsistency measures based on the vectorial inconsistency measure, which allow us to capture the inconsistency for a belief base in terms of a single numerical value as usual. We also show that each of the two kinds of revised inconsistency measures can be considered as a particular Shapley Inconsistency Value, and can be axiomatically characterized by the corresponding revised axioms presented in this paper.

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The phenomenon of paediatric social admission describes the hospitalisation of children for medicallynon- urgent and/or social reasons. Much of the research in this field has been in relation to avoidable admissions which have been identified, studied and condoned based on strict medical criteria. Such research has tended to mask the significance of social factors and the commonplace practice of Paediatric Social Admission. This paper examines decision making from the perspective of the health professionals at the clinical coal face. It explores how health professionals are influenced by social, organisational and subjective factors which determine their decision to admit or not to admit a child to hospital. The paper reports findings from interviews with 27 health professionals involved in PSA and a document audit of 21 specific cases. In doing so it begins to address the inherent paradox of responding to a child and families social needs in a medical context.

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Suppliers are increasingly involved in buyer firms’ interorganizational new product development (NPD) teams. Yet the transfer of knowledge within this context may be subject to varying degrees of causal ambiguity, potentially limiting the effect of supplier involvement on performance. We develop a theoretical model exploring the effect of supplier involvement practices on the level of causal ambiguity within interorganizational NPD teams, and the subsequent impact on competitor imitation, new product advantage, and project performance. Our model also serves as a test of the paradox that causal ambiguity both inhibits imitation by competitors, but also adversely affects organisational outcomes. Results from an empirical study of 119 R&D intensive manufacturing firms in the United Kingdom largely support these hypotheses. Results from structural equation modeling show that supplier involvement orientation and long-term commitment lower causal ambiguity within interorganizational NPD teams. In turn, this lower causal ambiguity generates a new product advantage and increases project performance for the buyer firm, but has no significant effect on competitor imitation. Instead, competitor imitation is delayed by the extent to which the firm develops a new product advantage within the market. These results shed light on the causal ambiguity paradox showing that lower causal ambiguity during interorganizational new product development increases both product and project performance, but without reducing barriers to imitation. Product development managers are encouraged to utilize supplier involvement practices to minimise ambiguity in the NPD project, and to target their supplier involvement efforts on solving causally ambiguous technological problems to sustain a competitive advantage.

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We report on the electric-field-generated effects in the nematic phase of a twin mesogen formed of bent-core and calamitic units, aligned homeotropically in the initial ground state and examined beyond the dielectric inversion point. The bend-Freedericksz (BF) state occurring at the primary bifurcation and containing a network of umbilics is metastable; we focus here on the degenerate planar (DP) configuration that establishes itself at the expense of the BF state in the course of an anchoring transition. In the DP regime, normal rolls, broad domains, and chevrons (both defect-mediated and defect-free types) form at various linear defect-sites, in different regions of the frequency-voltage plane. A significant novel aspect common to all these patterned states is the sustained propagative instability, which does not seem explicable on the basis of known driving mechanisms.

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Travel literature's inherent intergenericity extends into the realm of the interaesthetic in Nicolas Bouvier's textual and photographic representations of Asia. Although produced as distinct narratives, successive editorial decisions and the layering of these two media in the mind of the reader have transformed Bouvier's already palimpsestic texts into fluid, phototextual constructs. This article will offer ‘contrapuntal’ readings of a selection of Bouvier's texts in relation to the photographs charting his intercultural encounters in China and Japan. Countering the relegation of these photographs to the conventional status of aide-mémoire, the article will consider the shifting relationships of complementarity, tension, or disjuncture between image and text. These relationships are characterised by slippage, subversion and paradox. Text does not ‘load’ image, and images do not illustrate text. Indeed, Bouvier's photographs frequently contest, modify, or debunk the textual narratives. Ultimately, the article will argue that Bouvier's representations of Asia, both textual and visual, offer a challenge to cultural essentialism, to self-other binaries, and to monolithic discourses of otherness.

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Since 1991 with the advent of globalization and economic liberalisation, basic conceptual and discursive changes are taking place in housing sector in India. The new changes suggest how housing affordability, quality and lifestyles reality is shifting for various segments of the population. Such shift not only reflects structural patterns but also stimulates an ongoing transition process. The paper highlights a twin impetus that continue to shape the ongoing transition: expanding middle class and their wealth - a category with distinctive lifestyles, desires and habits and corresponding ‘market defining’ of affordable housing standards - to articulate function of housing as a conceptualization of social reality in modern India. The paper highlights the contradictions and paradoxes, and the manner in which the concept of affordability, quality and lifestyles are embedded in both discourse and practice in India. The housing ‘dream’ currently being packaged and fed through to the middle class population has an upper middle class bias and is set to alienate those at the lower end of the middle-and low-income population. In the context of growing agreement and inevitability of market provision of ‘affordable housing’, the unbridled ‘market-defining’ of housing quality and lifestyles must be checked.