86 resultados para Centric fusion


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Both Anderson and Gatignon and the Uppsala internationalization model see the initial mode of foreign market entry and subsequent modes of operation as unilaterally determined by multinational enterprises (MNEs) arbitraging control and risk and increasing their commitment as they gain experience in the target market. OLI and internalization models do recognize that foreign market entry requires the bundling of MNE and complementary local assets, which they call location or country-specific advantages, but implicitly assume that those assets are freely accessible to MNEs. In contrast to both of these MNE-centric views, I explicitly consider the transactional characteristics of complementary local assets and model foreign market entry as the optimal assignment of equity between their owners and MNEs. By looking at the relative efficiency of the different markets in which MNE and complementary local assets are traded, and at how these two categories of assets match, I am able to predict whether equity will be held by MNEs or by local firms, or shared between them, and whether MNEs will enter through greenfields, brownfields, or acquisitions. The bundling model I propose has interesting implications for the evolution of the MNE footprint in host countries, and for the reasons behind the emergence of Dragon MNEs.

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The Burkholderia cepacia complex (Bcc) is a group of opportunistic bacteria chronically infecting the airways of patients with cystic fibrosis (CF). Several laboratories have shown that Bcc members, in particular B. cenocepacia, survive within a membrane-bound vacuole inside phagocytic and epithelial cells. We have previously demonstrated that intracellular B. cenocepacia causes a delay in phagosomal maturation, as revealed by impaired acidification and slow accumulation of the late phagolysosomal marker LAMP-1. In this study, we demonstrate that uninfected cystic fibrosis transmembrane conductance regulator (CFTR)-defective macrophages or normal macrophages treated with a CFTR-specific drug inhibitor display normal acidification. However, after ingestion of B. cenocepacia, acidification and phagolysosomal fusion of the bacteria-containing vacuoles occur in a lower percentage of CFTR-negative macrophages than CFTR-positive cells, suggesting that loss of CFTR function contributes to enhance bacterial intracellular survival. The CFTR-associated phagosomal maturation defect was absent in macrophages exposed to heat-inactivated B. cenocepacia and macrophages infected with a non-CF pathogen such as Salmonella enterica, an intracellular pathogen that once internalized rapidly traffics to acidic compartments that acquire lysosomal markers. These results suggest that not only a defective CFTR but also viable B. cenocepacia are required for the altered trafficking phenotype. We conclude that CFTR may play a role in the mechanism of clearance of the intracellular infection, as we have shown before that B. cenocepacia cells localized to the lysosome lose cell envelope integrity. Therefore, the prolonged maturation arrest of the vacuoles containing B. cenocepacia within cftr(-/-) macrophages could be a contributing factor in the persistence of the bacteria within CF patients.

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Burkholderia cenocepacia is an opportunistic pathogen causing serious infections in patients with cystic fibrosis. The widespread distribution of this bacterium in the environment suggests that it must adapt to stress to be able to survive. We identified in B. cenocepacia K56-2 a gene predicted to encode RpoE, the extra-cytoplasmic stress response regulator. The rpoE gene is the first gene of a predicted operon encoding proteins homologous to RseA, RseB, MucD and a protein of unknown function. The genomic organization and the co-transcription of these genes were confirmed by PCR and RT-PCR. The mucD and rpoE genes were mutated, giving rise to B. cenocepacia RSF24 and RSF25, respectively. While mutant RSF24 did not demonstrate any growth defects under the conditions tested, RSF25 was compromised for growth under temperature (44 degrees C) and osmotic stress (426 mM NaCl). Expression of RpoE in trans could complement the osmotic growth defect but exacerbated temperature sensitivity in both RSF25 and wild-type K56-2. Inactivation of rpoE altered the bacterial cell surface, as indicated by increased binding of the fluorescent dye calcofluor white and by an altered outer-membrane protein profile. These cell surface changes were restored by complementation with a plasmid encoding rpoE. Macrophage infections in which bacterial colocalization with fluorescent dextran was examined demonstrated that the rpoE mutant could not delay the fusion of B. cenocepacia-containing vacuoles with lysosomes, in contrast to the parental strain K56-2. These data show that B. cenocepacia rpoE is required for bacterial growth under certain stress conditions and for the ability of intracellular bacteria to delay phagolysosomal fusion in macrophages.

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Most social scientists endorse some version of the claim that participating in collective rituals promotes social cohesion. The systematic testing and evaluation of this claim, however, has been prevented by a lack of precision regarding the nature of both ‘ritual’and ‘social cohesion’ as well as a lack of integration between the theories and findings of the social and evolutionary sciences. By directly addressing these challenges, we argue that a systematic investigation and evaluation of the claim that ritual promotes social cohesion is achievable.

We present a general and testable theory of the relationship between ritual, cohesion, and cooperation that more precisely connects particular elements of ‘ritual,’ such as causal opacity and emotional arousal, to two particular forms
of ‘social cohesion’: group identification and identity fusion. Further, we ground this theory in an evolutionary account of why particular modes of ritual practice would be adaptive for societies with particular resource acquisition strategies. In setting out our conceptual framework we report numerous ongoing investigations that test our hypotheses against data from controlled psychological experiments as well as from theethnographic, archaeological, and historical records.

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A general approach to information correction and fusion for belief functions is proposed, where not only may the information items be irrelevant, but sources may lie as well. We introduce a new correction scheme, which takes into account uncertain metaknowledge on the source’s relevance and truthfulness and that generalizes Shafer’s discounting operation. We then show how to reinterpret all connectives of Boolean logic in terms of source behavior assumptions with respect to relevance and truthfulness. We are led to generalize the unnormalized Dempster’s rule to all Boolean connectives, while taking into account the uncertainties pertaining to assumptions concerning the behavior of sources. Eventually, we further extend this approach to an even more general setting, where source behavior assumptions do not have to be restricted to relevance and truthfulness.We also establish the commutativity property between correction and fusion processes, when the behaviors of the sources are independent.

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When multiple sources provide information about the same unknown quantity, their fusion into a synthetic interpretable message is often a tedious problem, especially when sources are conicting. In this paper, we propose to use possibility theory and the notion of maximal coherent subsets, often used in logic-based representations, to build a fuzzy belief structure that will be instrumental both for extracting useful information about various features of the information conveyed by the sources and for compressing this information into a unique possibility distribution. Extensions and properties of the basic fusion rule are also studied.

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Protein interactions play key roles throughout all subcellular compartments. In the present paper, we report the visualization of protein interactions throughout living mammalian cells using two oligomerizing MV (measles virus) transmembrane glycoproteins, the H (haemagglutinin) and the F (fusion) glycoproteins, which mediate MV entry into permissive cells. BiFC (bimolecular fluorescence complementation) has been used to examine the dimerization of these viral glycoproteins. The H glycoprotein is a type II membrane-receptor-binding homodimeric glycoprotein and the F glycoprotein is a type I disulfide-linked membrane glycoprotein which homotrimerizes. Together they co-operate to allow the enveloped virus to enter a cell by fusing the viral and cellular membranes. We generated a pair of chimaeric H glycoproteins linked to complementary fragments of EGFP (enhanced green fluorescent protein)--haptoEGFPs--which, on association, generate fluorescence. Homodimerization of H glycoproteins specifically drives this association, leading to the generation of a fluorescent signal in the ER (endoplasmic reticulum), the Golgi and at the plasma membrane. Similarly, the generation of a pair of corresponding F glycoprotein-haptoEGFP chimaeras also produced a comparable fluorescent signal. Co-expression of H and F glycoprotein chimaeras linked to complementary haptoEGFPs led to the formation of fluorescent fusion complexes at the cell surface which retained their biological activity as evidenced by cell-to-cell fusion.

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This study presents the findings of an empirical channel characterisation for an ultra-wideband off-body optic fibre-fed multiple-antenna array within an office and corridor environment. The results show that for received power experiments, the office and corridor were best modelled by lognormal and Rician distributions, respectively [for both line of sight (LOS) and non-LOS (NLOS) scenarios]. In the office, LOS measurements for t and tRMS were both described by the Normal distribution for all channels, whereas NLOS measurements for t and t were Nakagami and Weibull distributed, respectively. For the corridor measurements, LOS for t and t were either Nakagami or normally distributed for all channels, with NLOS measurements for t and t being Nakagami and normally distributed, respectively. This work also shows that achievable diversity gain was influenced by both mutual coupling and cross-correlation co-efficients. Although the best diversity gains were 1.8 dB for three-channel selective diversity combining, the authors present recommendations for improving these results. © The Institution of Engineering and Technology 2013.

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Object tracking is an active research area nowadays due to its importance in human computer interface, teleconferencing and video surveillance. However, reliable tracking of objects in the presence of occlusions, pose and illumination changes is still a challenging topic. In this paper, we introduce a novel tracking approach that fuses two cues namely colour and spatio-temporal motion energy within a particle filter based framework. We conduct a measure of coherent motion over two image frames, which reveals the spatio-temporal dynamics of the target. At the same time, the importance of both colour and motion energy cues is determined in the stage of reliability evaluation. This determination helps maintain the performance of the tracking system against abrupt appearance changes. Experimental results demonstrate that the proposed method outperforms the other state of the art techniques in the used test datasets.

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We investigate whether the presence of a human body in wearable communications should be considered as part of the radiating structure or as part of the local radio environment. The Rician $K$ -factor was employed as a quantitative measure of the effect of the user's body for five environments and two mounting locations. Presented empirical results indicated that the environment had a greater impact on the $K$-factor values than the position of the transmit antenna for the ultrawideband signals used, confirming that the human body should be considered primarily as part of the overall radiating system when the antenna is worn on the body. Furthermore, independent variations also existed in the $K$-factor values for the differing antenna-body mounting positions, indicating that as the position changed, then the radiating effects and the contribution from the body changed. This is significant for ensuring body-antenna systems are accurately modeled in system-level simulations.

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This paper presents a new statistical signal reception model for shadowed body-centric communications channels. In this model, the potential clustering of multipath components is considered alongside the presence of elective dominant signal components. As typically occurs in body-centric communications channels, the dominant or line-of-sight (LOS) components are shadowed by body matter situated in the path trajectory. This situation may be further exacerbated due to physiological and biomechanical movements of the body. In the proposed model, the resultant dominant component which is formed by the phasor addition of these leading contributions is assumed to follow a lognormal distribution. A wide range of measured and simulated shadowed body-centric channels considering on-body, off-body and body-to-body communications are used to validate the model. During the course of the validation experiments, it was found that, even for environments devoid of multipath or specular reflections generated by the local surroundings, a noticeable resultant dominant component can still exist in body-centric channels where the user's body shadows the direct LOS signal path between the transmitter and the receiver.