5 resultados para Bridge failures
em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain
Resumo:
The European Neighbourhood Policy’s birth has taken place in parallel with the renewed momentum of the European Security and Defence Policy, which has launched 14 operations since 2003. Both policies’ instruments have converged in the neighbouring area covered by ENP: Georgia, in the East and the Palestinian Territories in the South. In both cases, the Security Sector Reform strategies have been the main focus for ESDP and an important objective for ENP. In this paper, two objectives are pursued: first, to assess the EU’s involvement in both cases in SSR terms; and second, to analyse whether the convergence of ESDP operations with a broader EU neighbourhood policy implies that the former has become an instrument for the a EU external action.
Resumo:
In this paper we study the optimal ex-ante merger policy in a model where merger proposals are the result of strategic bargaining among alternative candidates. We allow for firm asymmetries and, in particular, we emphasize the fact that potential synergies generated by a merger may vary substantially depending on the identity of the participating firms. The model demonstrates that, under some circumstances, relatively inefficient mergers may take place. That is, a particular merger may materialize despite the existence of an alternative merger capable of generating higher social surplus and even higher profits. Such bargaining failures have important implications for the ex-ante optimal merger policy. We show that a more stringent policy than the ex-post optimal reduces the scope of these bargaining failures and raises expected social surplus. We use a bargaining model that is flexible, in the sense that its strategic structure does not place any exogenous restriction on the endogenous likelihood of feasible mergers.
Resumo:
Comparison of donor-acceptor electronic couplings calculated within two-state and three-state models suggests that the two-state treatment can provide unreliable estimates of Vda because of neglecting the multistate effects. We show that in most cases accurate values of the electronic coupling in a π stack, where donor and acceptor are separated by a bridging unit, can be obtained as Ṽ da = (E2 - E1) μ12 Rda + (2 E3 - E1 - E2) 2 μ13 μ23 Rda2, where E1, E2, and E3 are adiabatic energies of the ground, charge-transfer, and bridge states, respectively, μij is the transition dipole moments between the states i and j, and Rda is the distance between the planes of donor and acceptor. In this expression based on the generalized Mulliken-Hush approach, the first term corresponds to the coupling derived within a two-state model, whereas the second term is the superexchange correction accounting for the bridge effect. The formula is extended to bridges consisting of several subunits. The influence of the donor-acceptor energy mismatch on the excess charge distribution, adiabatic dipole and transition moments, and electronic couplings is examined. A diagnostic is developed to determine whether the two-state approach can be applied. Based on numerical results, we showed that the superexchange correction considerably improves estimates of the donor-acceptor coupling derived within a two-state approach. In most cases when the two-state scheme fails, the formula gives reliable results which are in good agreement (within 5%) with the data of the three-state generalized Mulliken-Hush model
Resumo:
This paper proposes an explanation as to why some mergers fail, based on the interactionbetween the pre- and post-merger processes. We argue that failure may stem from informationalasymmetries arising from the pre-merger period, and problems of cooperation andcoordination within recently merged firms. We show that a partner may optimally agree tomerge and abstain from putting forth any post-merger effort, counting on the other partnerto make the necessary efforts. If both follow the same course of action, the merger goesahead but fails. Our unique equilibrium allows us to make predictions on which mergers aremore likely to fail.
Resumo:
Acute variceal bleeding (AVB) is a life-threatening complication in patients with cirrhosis. Hemostatic therapy of AVB includes early administration of vasoactive drugs that should be combined with endoscopic therapy, preferably banding ligation. However, failure to control bleeding or early rebleed within 5 days still occurs in 15-20% of patients with AVB. In these cases, a second endoscopic therapy may be attempted (mild bleeding in a hemodynamically stable patient) or we can use a balloon tamponade as a bridge to definitive derivative treatment (i.e., a transjugular intrahepatic portosystemic shunt). Esophageal balloon tamponade provides initial control in up to 80% of AVB, but it carries a high risk of major complications, especially in cases of long duration of tamponade (>24 h) and when tubes are inserted by inexperienced staff. Preliminary reports suggest that self-expandable covered esophageal metallic stents effectively control refractory AVB (i.e., ongoing bleeding despite pharmacological and endoscopic therapy or massive bleeding precluding endoscopic therapy) with a low incidence of complications. Thus, covered self-expanding metal stents may represent an alternative to the Sengstaken-Blakemore balloon for the temporary control of bleeding in treatment failures. Further studies are required to determine the role of this new device in AVB.