Search

Background A multidisciplinary international working subgroup of the third Perioperative Quality Initiative consensus meeting appraised the evidence on the influence of preoperative arterial blood pressure and community cardiovascular medications on perioperative risk. Methods A modified Delphi technique was used, evaluating papers published in MEDLINE on associations between preoperative numerical arterial pressure values or cardiovascular medications and perioperative outcomes. The strength of the recommendations was graded by National Institute for Health and Care Excellence guidelines. Results Significant heterogeneity in study design, including arterial pressure measures and perioperative outcomes, hampered the comparison of studies. Nonetheless, consensus recommendations were that (i) preoperative arterial pressure measures may be used to define targets for perioperative management; (ii) elective surgery should not be cancelled based solely upon a preoperative arterial pressure value; (iii) there is insufficient evidence to support lowering arterial pressure in the immediate preoperative period to minimise perioperative risk; and (iv) there is insufficient evidence that any one measure of arterial pressure (systolic, diastolic, mean, or pulse) is better than any other for risk prediction of adverse perioperative events. Conclusions Future research should define which preoperative arterial pressure values best correlate with adverse outcomes, and whether modifying arterial pressure in the preoperative setting will change the perioperative morbidity or mortality. Additional research should define optimum strategies for continuation or discontinuation of preoperative cardiovascular medications.

The protection of civilians (PoC) mandate of the United Nations Mission in South Sudan (UNMISS), was established in 2011, coinciding with the country's independence. Since then, the public discourse on UNMISS has called into question the capacity of the mission to fully meet the expectations created by this mandate in practice. In this chapter we explore this issue by investigating the following questions: 1) how can the discrepancy between UNMISS and its mandate be understood within the context of international law? 2) what does the quantitative data available on incidents requiring civilian protection indicate regarding who were the actors involved, the frequency and distribution of events, and the extent of documented fatalities?; 3) what does the public discourse (media accounts, academic publications, as well as UN and third-party investigations) reveal about UNMISS and its PoC mandate? To answer these questions, we first present the international legal context in which the mission operates, and identify key areas of concern. We then analyze incidents that took place in the national capital, Juba, as well as the state capitals of Malakal and Bor, to highlight the challenges facing UNMISS in protecting civilians in South Sudan. We make use of data from the Armed Conflict Location & Event Data Project (ACLED), concentrating on incidents that occurred in South Sudan between 2011 and 2016. This data is then traced to the public discourse that exists on UNMISS and its mandate. We find that there remain contradictions between the actions of the peacekeeping force and the mandate of UNMISS, the public expectations of the institution, as well as the resources and personnel provided to support its activities. We conclude by proposing that a path forward be created that involves robust and citizen-centered peacekeeping.

MAAP4 is a computer code that can simulate the response of a light water reactor power plant during severe accident sequences, including actions taken as part of accident management. The code quantitatively predicts the evolution of a severe accident starting from full power conditions given a set of system faults and initiating events through events such as core melt, reactor vessel failure, and containment failure. Furthermore, models are included in the code to represent the actions that could mitigate the accident by in-vessel cooling, external cooling of the reactor pressure vessel, or cooling the debris in containment. A key element tied to using a code like MAAP4 is an uncertainty analysis. The purpose of this paper is to present a MAAP4 based analysis to examine the sensitivity of a key parameter, in this case hydrogen production, to a set of model parameters that are related to a Level 2 PRA analysis. The Level 2 analysis examines those sequences that result in core melting and subsequent reactor pressure vessel failure and its impact on the containment. This paper identifies individual contributors and MAAP4 model parameters that statistically influence hydrogen production. Hydrogen generation was chosen because of its direct relationship to oxidation. With greater oxidation, more heat is added to the core region and relocation (core slump) should occur faster. This, in theory, would lead to shorter failure times and subsequent “hotter” debris pool on the containment floor.