General Relativistic Cosmological N-body Simulations I: time integration

This is the first in a series of papers devoted to fully general-relativistic $N$-body simulations applied to late-time cosmology. The purpose of this paper is to present the combination of a numerical relativity scheme, discretization method and time-integration algorithm that provides satisfyingly stable evolution. More precisely, we show that it is able to pass a robustness test and to follow scalar linear modes around an expanding homogeneous and isotropic space-time. Most importantly, it is able to evolve typical cosmological initial conditions on comoving scales down to tenths of megaparsecs with controlled constraint and energy-momentum conservation violations all the way down to the regime of strong inhomogeneity.Comment: 28 pages, 16 figure

A numerical relativity scheme for cosmological simulations

Cosmological simulations involving the fully covariant gravitational dynamics may prove relevant in understanding relativistic/non-linear features and, therefore, in taking better advantage of the upcoming large scale structure survey data. We propose a new 3+1 integration scheme for General Relativity in the case where the matter sector contains a minimally-coupled perfect fluid field. The original feature is that we completely eliminate the fluid components through the constraint equations, thus remaining with a set of unconstrained evolution equations for the rest of the fields. This procedure does not constrain the lapse function and shift vector, so it holds in arbitrary gauge and also works for arbitrary equation of state. An important advantage of this scheme is that it allows one to define and pass an adaptation of the robustness test to the cosmological context, at least in the case of pressureless perfect fluid matter, which is the relevant one for late-time cosmology.Comment: 14 pages, 3 figures, matches published versio

Human rights : bioethical and biopolitical implications of torture

9th Annual Ethics Conference. Theme : Bioethics medical, legal, environmental and cultural aspects in healthcare ethics at Strathmore University, 25-26 October 2012.9th Annual Ethics Conference. Theme : Bioethics medical, legal, environmental and cultural aspects in healthcare ethics at Strathmore University, 25-26 October 2012

gevolution: a cosmological N-body code based on General Relativity

We present a new N-body code, gevolution, for the evolution of large scale structure in the Universe. Our code is based on a weak field expansion of General Relativity and calculates all six metric degrees of freedom in Poisson gauge. N-body particles are evolved by solving the geodesic equation which we write in terms of a canonical momentum such that it remains valid also for relativistic particles. We validate the code by considering the Schwarzschild solution and, in the Newtonian limit, by comparing with the Newtonian N-body codes Gadget-2 and RAMSES. We then proceed with a simulation of large scale structure in a Universe with massive neutrinos where we study the gravitational slip induced by the neutrino shear stress. The code can be extended to include different kinds of dark energy or modified gravity models and going beyond the usually adopted quasi-static approximation. Our code is publicly available.Comment: 28 pages + appendix, 10 figures. v2: revised and extended version accepted by JCAP; code available at https://github.com/gevolution-cod

IL DESIGN DEI BENI CULTURALI.CRISI TERRITORIO, IDENTITÀ

Sino a pochi anni fa accostare il termine Design a quello di Beni Culturali avrebbe avuto il sapore di una provocazione. Un evidente ossimoro, insomma, tra una parola -Design- per sua natura legata all’idea del nuovo e un’altra -Beni Culturali- evidentemente connessa alla conservazione dell’antico. Se il Design inoltre rimandava quasi automaticamente a una modalità del progetto fondata ancora largamente sul riferimento al paradigma industriale, i Beni Culturali evocavano una concezione “patrimoniale” del lascito storico, per la massima parte individuato nel paesaggio e nei “beni” ereditati dalla cultura delle età preindustriali. E’ dunque evidente che la nuova dizione di Design dei Beni Culturali è il frutto di una progressiva, doppia rivoluzione che ha modificato sia la nostra percezione del concetto di “bene” legato al passato, sia il campo di significati attribuiti alle pratiche del progetto industriale. Il design investe i Beni Culturali con tutto il peso delle nuove tecnologie -del digitale e del virtuale innanzitutto- facendole entrare prepotentemente nel territorio dei musei, dell’archeologia, dell’archivistica, ma anche nella valorizzazione in tempo di crisi delle risorse territoriali diffuse nei contesti urbani e territoriali.Up until just a few years ago, putting the terms “design” and “cultural heritage” together would have sounded like a provocation. An obvious oxymoron, really, between one word – design - by its nature tied to the idea of the new and another – cultural heritage – clearly connected to the conservation of the old. Furthermore, while “design” almost automatically turned to a design process still largely based on the industrial paradigm, “cultural heritage” evoked an interpretation of history’s legacy as “endowments”, for the most part identified in the landscape and in assets inherited from pre-industrial cultures. This new wording of the “design of cultural heritage is the result of a progressive double revolution, which has changed both our perception of the concept of “asset” tied to the past, as well as the range of meanings attributed to the industrial design process. Today, design invests cultural heritage in particular with an armament of new technologies – spanning from digital to virtual,– makes them important protagonists in the fields of museums, archaeology, archiving, but also in the development, in times of crisis, of cultural recourses spread throughout the urban and regional context

Implementation and impact of pediatric antimicrobial stewardship programs: a systematic scoping review.

Background: Antibiotics are the most common medicines prescribed to children in hospitals and the community, with a high proportion of potentially inappropriate use. Antibiotic misuse increases the risk of toxicity, raises healthcare costs, and selection of resistance. The primary aim of this systematic review is to summarize the current state of evidence of the implementation and outcomes of pediatric antimicrobial stewardship programs (ASPs) globally. Methods: MEDLINE, Embase and Cochrane Library databases were systematically searched to identify studies reporting on ASP in children aged 0-18 years and conducted in outpatient or in-hospital settings. Three investigators independently reviewed identified articles for inclusion and extracted relevant data. Results: Of the 41,916 studies screened, 113 were eligible for inclusion in this study. Most of the studies originated in the USA (52.2%), while a minority were conducted in Europe (24.7%) or Asia (17.7%). Seventy-four (65.5%) studies used a before-and-after design, and sixteen (14.1%) were randomized trials. The majority (81.4%) described in-hospital ASPs with half of interventions in mixed pediatric wards and ten (8.8%) in emergency departments. Only sixteen (14.1%) studies focused on the costs of ASPs. Almost all the studies (79.6%) showed a significant reduction in inappropriate prescriptions. Compliance after ASP implementation increased. Sixteen of the included studies quantified cost savings related to the intervention with most of the decreases due to lower rates of drug administration. Seven studies showed an increased susceptibility of the bacteria analysed with a decrease in extended spectrum beta-lactamase producers E. coli and K. pneumoniae; a reduction in the rate of P. aeruginosa carbapenem resistance subsequent to an observed reduction in the rate of antimicrobial days of therapy; and, in two studies set in outpatient setting, an increase in erythromycin-sensitive S. pyogenes following a reduction in the use of macrolides. Conclusions: Pediatric ASPs have a significant impact on the reduction of targeted and empiric antibiotic use, healthcare costs, and antimicrobial resistance in both inpatient and outpatient settings. Pediatric ASPs are now widely implemented in the USA, but considerable further adaptation is required to facilitate their uptake in Europe, Asia, Latin America and Africa