60 research outputs found

    State-space Manifold and Rotating Black Holes

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    We study a class of fluctuating higher dimensional black hole configurations obtained in string theory/ MM-theory compactifications. We explore the intrinsic Riemannian geometric nature of Gaussian fluctuations arising from the Hessian of the coarse graining entropy, defined over an ensemble of brane microstates. It has been shown that the state-space geometry spanned by the set of invariant parameters is non-degenerate, regular and has a negative scalar curvature for the rotating Myers-Perry black holes, Kaluza-Klein black holes, supersymmetric AdS5AdS_5 black holes, D1D_1-D5D_5 configurations and the associated BMPV black holes. Interestingly, these solutions demonstrate that the principal components of the state-space metric tensor admit a positive definite form, while the off diagonal components do not. Furthermore, the ratio of diagonal components weakens relatively faster than the off diagonal components, and thus they swiftly come into an equilibrium statistical configuration. Novel aspects of the scaling property suggest that the brane-brane statistical pair correlation functions divulge an asymmetric nature, in comparison with the others. This approach indicates that all above configurations are effectively attractive and stable, on an arbitrary hyper-surface of the state-space manifolds. It is nevertheless noticed that there exists an intriguing relationship between non-ideal inter-brane statistical interactions and phase transitions. The ramifications thus described are consistent with the existing picture of the microscopic CFTs. We conclude with an extended discussion of the implications of this work for the physics of black holes in string theory.Comment: 44 pages, Keywords: Rotating Black Holes; State-space Geometry; Statistical Configurations, String Theory, M-Theory. PACS numbers: 04.70.-s Physics of black holes; 04.70.Bw Classical black holes; 04.70.Dy Quantum aspects of black holes, evaporation, thermodynamics; 04.50.Gh Higher-dimensional black holes, black strings, and related objects. Edited the bibliograph

    Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

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    Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

    Cryopreservation of mammalian oocytes and embryos: current problems and future perspectives

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    A better life: the implementation and effect of person-centred active support in the Avenues Trust

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    Engagement in meaningful active and relationships is important for quality of life but, for those with intellectual and developmental disabilities, engagement depends on the quality of support received from those around them. This paper describes the process of implementing person-centred active support in the Avenues Trust, and the findings from the evaluation of the implementation in six pilot residential services. Attention was paid both to training staff and to the motivational structures within the organisation. Both the quality of support provided by staff and the level of engagement increased significantly after the introduction of person-centred active support. In addition, people experienced decreased self-stimulatory and injurious behaviour, increased opportunities for choice and control, and higher levels of participation in tasks of daily living, without compromising their community involvement. Staff experienced more and better practice leadership, and staff morale improved within the services, with staff generally more positive about management, more satisfied and less likely to leave. Lessons learnt about the implementation are provided

    A Synthesis of Top-Down and Bottom-Up Impacts of the Deepwater Horizon Oil Spill Using Ecosystem Modeling

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    The Deepwater Horizon (DWH) oil spill in the Gulf of Mexico (GoM) triggered the largest response to a spill in US history (Levy and Gopalakrishnan, J Nat Resources Pol Res, 2(3):297–315, 2010; Barron, Toxicol Pathol 40(2):315–320, 2012). The cumulative research from this response has resulted in hundreds of publications describing the range of impacts from the DWH event on various components of the system. An ecosystem-based approach to assessing the consequences of the DWH oil spill can help to address non-linear and ecosystem-level interactions (reviewed by Curtin and Prellezo, Mar Policy 34(5):821–830, 2010) and would be a key step toward integrating the knowledge gained from research efforts. Whereas Ainsworth et al. (PLoS One 13(1):e0190840, 2018) tested top-down effects of the oil spill on fish abundance and mortality, this chapter represents a synthesis of bottom-up and top-down effects across a broader range of taxa. Bottom-up effects relate to the accumulation of detrital biomass and oil on the seafloor as a result of marine oil snow sedimentation and flocculent accumulation (MOSSFA)
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