2,926 research outputs found

    Integrability of Dirac reduced bi-Hamiltonian equations

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    First, we give a brief review of the theory of the Lenard-Magri scheme for a non-local bi-Poisson structure and of the theory of Dirac reduction. These theories are used in the remainder of the paper to prove integrability of three hierarchies of bi-Hamiltonian PDE's, obtained by Dirac reduction from some generalized Drinfeld-Sokolov hierarchies.Comment: 15 pages. Corrected some typos and added missing equations in Section 5 for g=sl_n, n>

    Dissociative symptoms and the quality of structural integration in borderline personality disorder

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    Background Transient dissociation is a core feature of borderline personality disorder (BPD). Dissociation is characterized by detachment from reality, which can be mild (e.g. daydreaming) to severe (e.g. depersonalization, amnesia). High levels of dissociation are linked to more severe psychopathology and likely to impede therapy effectiveness. Objective Assessing the efficacy of psychological interventions in reducing dissociation in BPD and the impact of dissociation on therapy outcome. Results Psychological interventions were not found to be superior to treatment as usual. A small number of studies showed that higher dissociation at baseline predicted greater improvement. The use of narrative building techniques also showed related to reduce dissociation. Conclusion The evidence-base for treating dissociation is fairly limited. Standard interventions for BPD show promising results, but further research is required. Methods An electronic search of Psychinfo, Medline and Embase along with a hand search of relevant papers identified 20 studies

    A model for assessing the systemic vulnerability in landslide prone areas

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    Abstract. The objectives of spatial planning should include the definition and assessment of possible mitigation strategies regarding the effects of natural hazards on the surrounding territory. Unfortunately, however, there is often a lack of adequate tools to provide necessary support to the local bodies responsible for land management. This paper deals with the conception, the development and the validation of an integrated numerical model for assessing systemic vulnerability in complex and urbanized landslide-prone areas. The proposed model considers this vulnerability not as a characteristic of a particular element at risk, but as a peculiarity of a complex territorial system, in which the elements are reciprocally linked in a functional way. It is an index of the tendency of a given territorial element to suffer damage (usually of a functional kind) due to its interconnections with other elements of the same territorial system. The innovative nature of this work also lies in the formalization of a procedure based on a network of influences for an adequate assessment of such "systemic" vulnerability. This approach can be used to obtain information which is useful, in any given situation of a territory hit by a landslide event, for the identification of the element which has suffered the most functional damage, ie the most "critical" element and the element which has the greatest repercussions on other elements of the system and thus a "decisive" role in the management of the emergency. This model was developed within a GIS system through the following phases: 1. the topological characterization of the territorial system studied and the assessment of the scenarios in terms of spatial landslide hazard. A statistical method, based on neural networks was proposed for the assessment of landslide hazard; 2. the analysis of the direct consequences of a scenario event on the system; 3. the definition of the assessment model of systemic vulnerability in landslide-prone areas. To highlight the potentialities of the proposed approach we have described a specific case study of landslide hazard in the local council area of Potenza

    Flood-risk assessment and hazard mitigation mesures : case studies and lessons learnt in Italy

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    The effect of climate change and the growing world population are together increaing both the chance of flooding and the consequences. In Italy , in the wake of the floods that plagued the northen part of the country in the fifties and sixties ,a process was set in motion aimed at developing a new integrated approach to water management, at the catchment level,suitable for coping with water related disasters.In this context,three case-studies of flood risk management and hazard assessment are described

    Preferential attachment in the protein network evolution

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    The Saccharomyces cerevisiae protein-protein interaction map, as well as many natural and man-made networks, shares the scale-free topology. The preferential attachment model was suggested as a generic network evolution model that yields this universal topology. However, it is not clear that the model assumptions hold for the protein interaction network. Using a cross genome comparison we show that (a) the older a protein, the better connected it is, and (b) The number of interactions a protein gains during its evolution is proportional to its connectivity. Therefore, preferential attachment governs the protein network evolution. The evolutionary mechanism leading to such preference and some implications are discussed.Comment: Minor changes per referees requests; to appear in PR

    An Independent Judiciary: The Role of Chief Justice Cappy

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    Effect of host kairomones and oviposition experience on the arrestment behavior of an egg parasitoid

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    Chemical residues left by walking adults of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae) induce arrestment behavior in the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) leading to prolonged periods of walking on contaminated areas and to systematic return to the stimulus after encountering the treatment borders. In this study, we quantified how the hierarchical value of residues from host adults and oviposition experience can influence the arrestment behavior of T. basalis females. Our results showed that: (1) female wasps perceived host residues at different hierarchical levels depending on the host gender, with a clear preference for the chemical residues deposited by host females rather then host males; (2) wasps' arrestment response to chemical residues of host females became weaker when wasps were not rewarded by an oviposition experience, and stronger following successful oviposition; (3) repeated encounters with host male chemical residues, followed or not by oviposition experience, did not cause wasps to change their innate arrestment response; (4) in the unrewarded condition, arrestment responses of wasps varied according to the time elapsed between successive visits to areas contaminated by host females: responses were weak with a short interval (less than 24 h) and stronger with a long interval (more than 72 h), suggesting that this unrewarded experience, i.e. encounter with female traces not followed by host egg location, fade within a few hours. The potential significance of these results to the host location behavior of T. basalis in the field is discussed

    Bihamiltonian Cohomologies and Integrable Hierarchies I: A Special Case

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    We present some general results on properties of the bihamiltonian cohomologies associated to bihamiltonian structures of hydrodynamic type, and compute the third cohomology for the bihamiltonian structure of the dispersionless KdV hierarchy. The result of the computation enables us to prove the existence of bihamiltonian deformations of the dispersionless KdV hierarchy starting from any of its infinitesimal deformations.Comment: 43 pages. V2: the accepted version, to appear in Comm. Math. Phy
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