Search results for "CME"

Hydrogen non-equilibrium ionisation effects in coronal mass ejections

2020

This research has received funding from the Science and Technology Facilities Council (UK) through the consolidated grant ST/N000609/1 and the European Research Council (ERC) under the European Union Horizon 2020 research and innovation program (grant agreement No. 647214). D.H.M. would like to thank both the UK STFC and the ERC (Synergy grant: WHOLE SUN, grant Agreement No. 810218) for financial support. D.H.M. and P.P. would like to thank STFC for IAA funding under grant number SMC1-XAS012. This work used the DiRAC@Durham facility man-aged by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility (www.dirac.ac.uk. The equipment was funded by BEIS capital fundin…

Determining the source and eruption dynamics of a stealth CME using NLFFF modelling and MHD simulations

2021

Coronal mass ejections (CMEs) that exhibit weak or no eruption signatures in the low corona, known as stealth CMEs, are problematic as upon arrival at Earth they can lead to geomagnetic disturbances that were not predicted by space weather forecasters. We investigate the origin and eruption of a stealth event that occurred on 2015 January 3 that was responsible for a strong geomagnetic storm upon its arrival at Earth. To simulate the coronal magnetic field and plasma parameters of the eruption we use a coupled approach. This approach combines an evolutionary nonlinear force-free field model of the global corona with a MHD simulation. The combined simulation approach accurately reproduces th…

Effect of gravitational stratification on the propagation of a CME

2013

Our aim is to study the role of gravitational stratification on the propagation of CMEs. In particular, we assess how it influences the speed and shape of CMEs and under what conditions the flux rope ejection becomes a CME or when it is quenched. We ran a set of MHD simulations that adopt an eruptive initial magnetic configuration that has already been shown to be suitable for a flux rope ejection. We varied the temperature of the backgroud corona and the intensity of the initial magnetic field to tune the gravitational stratification and the amount of ejected magnetic flux. We used an automatic technique to track the expansion and the propagation of the magnetic flux rope in the MHD simula…

Simulating AIA observations of a flux rope ejection

2014

D.H.M. would like to thank STFC, the Leverhulme Trust and the European Commission’s Seventh Framework Programme (FP7/2007-2013) for their financial support. P.P. would like to thank the European Commission’s Seventh Framework Programme (FP7/2007-2013) under grant agreement SWIFF (project 263340, http://www.swiff.eu) and STFC for financial support. These results were obtained in the framework of the projects GOA/2009-009 (KU Leuven), G.0729.11 (FWO-Vlaanderen) and C 90347 (ESA Prodex 9). The research leading to these results has also received funding from the European Commission’s Seventh Framework Programme (FP7/2007-2013) under the grant agreements SOLSPANET (project No. 269299, http:// ww…

Future capabilities of CME polarimetric 3D reconstructions with the METIS instrument: A numerical test

2015

D.H.M. would like to thank STFC and the Leverhulme Trust for their financial support. P.P. would like to thank STFC and the Leverhulme Trust. The computational work for this paper was carried out on the joint STFC and SFC (SRIF) funded cluster at the University of St Andrews (Scotland, UK). Context. Understanding the 3D structure of coronal mass ejections (CMEs) is crucial for understanding the nature and origin of solar eruptions. However, owing to the optical thinness of the solar corona we can only observe the line of sight integrated emission. As a consequence the resulting projection effects hide the true 3D structure of CMEs. To derive information on the 3D structure of CMEs from whit…

High frequencies of antibiotic resistance genes in infants' meconium and early fecal samples

2016

The gastrointestinal tract (GIT) microbiota has been identified as an important reservoir of antibiotic resistance genes (ARGs) that can be horizontally transferred to pathogenic species. Maternal GIT microbes can be transmitted to the offspring, and recent work indicates that such transfer starts before birth. We have used culture-independent genetic screenings to explore whether ARGs are already present in the meconium accumulated in the GIT during fetal life and in feces of 1-week-old infants. We have analyzed resistance to β-lactam antibiotics (BLr) and tetracycline (Tcr), screening for a variety of genes conferring each. To evaluate whether ARGs could have been inherited by maternal tr…

Descriptive epidemiology of nasal carriage of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus among patients admitted to two he…

2014

Aim: To evaluate nasal carriage rate and variables associated with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted in two healthcare facilities. Results: S. aureus was isolated from 159 (26%) of the enrolled patients. Methicillin-susceptible S. aureus was isolated from 150 (24.5%) patients, and MRSA was isolated from 9 (1.5%). Cancer and previous hospitalization were associated with a significantly higher frequency of nasal S. aureus carriage among the patients admitted to the general hospital and the nephrology department, respectively. MRSA isolates were heterogeneous with respect to their staphylococcal cassette chromosome mec element (SC…

Ventilator-associated Pneumonia and MRSA ST398, Italy

2010

To the Editor: Methicillin-resistant Staphylococcus aureus (MRSA) sequence type (ST)398 has become increasingly common in livestock, particularly pigs, in some countries in Europe, such as Spain and Germany (1). In Italy, prevalences as high as 14% and 21.6% in pig-breeding facilities and meat-processing sites, respectively, have been recently reported (1). Possible association of MRSA in animals with infection in humans has been investigated. One study showed a strong relationship between contact with pigs or calves and carriage by persons having direct contact with animals and families of persons who handle animals (2). Moreover, an MRSA prevalence >11.9% has been described by de Boer et …

Debiasi, Andrea. Eumelo: un poeta per Corinto con ulteriori divagazioni epiche. Problemi e ricerche di storia antica, 31. Roma: "L’Erma" di Bretschne…

2017

Renforcer la mesure sur la qualité de l'éducation

2012

Les réflexions en cours sur le développement et les inégalités accroissent l'intérêt de mesurer les savoirs et les compétences des populations jeunes. Parmi les objectifs du Millénaire pour le développement, la lutte contre l'analphabétisme se fonde sur une éducation de qualité. La question de la création d'outils de mesure de la qualité de l'éducation est donc essentielle pour valider, universellement et équitablement, l'acquisition des apprentissages fondamentaux. Cette question est directement liée au développement, depuis 50 ans, de méthodes d'évaluation des acquisitions à l'origine des grandes enquêtes internationales comme PIRLS, TIMSS et PISA. Dans cet effort de connaissance sur la q…