49 research outputs found
How many-body correlations and -clustering shape He
The Borromean He nucleus is an exotic system characterized by two `halo'
neutrons orbiting around a compact He (or ) core, in which the
binary subsystems are unbound. The simultaneous reproduction of its small
binding energy and extended matter and point-proton radii has been a challenge
for {\em ab initio} theoretical calculations based on traditional bound-state
methods. Using soft nucleon-nucleon interactions based on chiral effective
field theory potentials, we show that supplementing the model space with
He++ cluster degrees of freedom largely solves this issue. We analyze
the role played by the -clustering and many-body correlations, and
study the dependence of the energy spectrum on the resolution scale of the
interaction.Comment: 5 pages, 4 figure
Advances in the ab initio description of nuclear three-cluster systems
We introduce the extension of the ab initio no-core shell model with
continuum to describe three-body cluster systems. We present results for the
ground state of 6He and show improvements with respect to the description
obtained within the no-core shell model and the no-core shell model/resonating
group methods.Comment: Proceedings of the 21st International Conference on Few-Body Problems
in Physics. May 18-22, 2015. Chicago, Illinois, US
Unified ab initio approaches to nuclear structure and reactions
The description of nuclei starting from the constituent nucleons and the
realistic interactions among them has been a long-standing goal in nuclear
physics. In addition to the complex nature of the nuclear forces, with two-,
three- and possibly higher many-nucleon components, one faces the
quantum-mechanical many-nucleon problem governed by an interplay between bound
and continuum states. In recent years, significant progress has been made in ab
initio nuclear structure and reaction calculations based on input from
QCD-employing Hamiltonians constructed within chiral effective field theory.
After a brief overview of the field, we focus on ab initio many-body approaches
- built upon the No-Core Shell Model - that are capable of simultaneously
describing both bound and scattering nuclear states, and present results for
resonances in light nuclei, reactions important for astrophysics and fusion
research. In particular, we review recent calculations of resonances in the
He halo nucleus, of five- and six-nucleon scattering, and an investigation
of the role of chiral three-nucleon interactions in the structure of Be.
Further, we discuss applications to the BeB radiative
capture. Finally, we highlight our efforts to describe transfer reactions
including the HHe fusion.Comment: Contribution to the Special Physica Scripta Edition - 40 year
anniversary - Nobel Prize '75, 71 pages, 29 figure
No-Core Shell Model Analysis of Light Nuclei
The fundamental description of both structural properties and reactions of
light nuclei in terms of constituent protons and neutrons interacting through
nucleon-nucleon and three-nucleon forces is a long-sought goal of nuclear
theory. I will briefly present a promising technique, built upon the {\em ab
initio} no-core shell model, which emerged recently as a candidate to reach
such a goal: the no-core shell model/resonating-group method. This approach,
capable of describing simultaneously both bound and scattering states in light
nuclei, complements a microscopic cluster technique with the use of two-nucleon
realistic interactions, and a microscopic and consistent description of the
nucleon clusters. I will discuss applications to light nuclei binary scattering
processes and fusion reactions that power stars and Earth based fusion
facilities, such as the deuterium-He fusion, and outline the progress
toward the inclusion of the three-nucleon force into the formalism and the
treatment of three-body clusters.Comment: 8 pages, 6 figures, Proceedings of the 20th International IUPAP
Conference on Few-Body Problems in Physics, 20 - 25 August, 2012, Fukuoka,
Japa
Seguimiento de la coordinación: Evaluación continua del curso 3 del Grado de Teleco de la EPS
Uno de los problemas que se ha introducido con la implantación de la evaluación continua en los nuevos grados es el exceso de carga de trabajo que conlleva la propia evaluación de las materias a lo largo del curso. Este ha sido un motivo de queja recurrente por parte de los estudiantes, los cuales se sienten estresados casi desde el comienzo del curso, llegando muchas veces a dejar de asistir durante determinados periodos a las clases para poder dedicar su atención a las evaluaciones. Esto último, a su vez, provoca quejas entre el profesorado por la no asistencia de sus estudiantes. Con el fin de mitigar esta situación, en el presente trabajo se ha realizado un estudio sobre la evaluación continua del tercer curso del Grado en Ingeniería en Sonido e Imagen en Telecomunicación de la Universidad de Alicante, y se ha consensuado un calendario de evaluación continua en el cual se intenta dosificar el esfuerzo que los estudiantes deberán realizar para sacar adelante el curso. Este trabajo está enmarcado dentro de los mecanismos de coordinación que fomenta la Escuela Politécnica Superior en sus grados
Effectiveness of an intervention for improving drug prescription in primary care patients with multimorbidity and polypharmacy:Study protocol of a cluster randomized clinical trial (Multi-PAP project)
This study was funded by the Fondo de Investigaciones Sanitarias ISCIII (Grant Numbers PI15/00276, PI15/00572, PI15/00996), REDISSEC (Project Numbers RD12/0001/0012, RD16/0001/0005), and the European Regional Development Fund ("A way to build Europe").Background: Multimorbidity is associated with negative effects both on people's health and on healthcare systems. A key problem linked to multimorbidity is polypharmacy, which in turn is associated with increased risk of partly preventable adverse effects, including mortality. The Ariadne principles describe a model of care based on a thorough assessment of diseases, treatments (and potential interactions), clinical status, context and preferences of patients with multimorbidity, with the aim of prioritizing and sharing realistic treatment goals that guide an individualized management. The aim of this study is to evaluate the effectiveness of a complex intervention that implements the Ariadne principles in a population of young-old patients with multimorbidity and polypharmacy. The intervention seeks to improve the appropriateness of prescribing in primary care (PC), as measured by the medication appropriateness index (MAI) score at 6 and 12months, as compared with usual care. Methods/Design: Design:pragmatic cluster randomized clinical trial. Unit of randomization: family physician (FP). Unit of analysis: patient. Scope: PC health centres in three autonomous communities: Aragon, Madrid, and Andalusia (Spain). Population: patients aged 65-74years with multimorbidity (≥3 chronic diseases) and polypharmacy (≥5 drugs prescribed in ≥3months). Sample size: n=400 (200 per study arm). Intervention: complex intervention based on the implementation of the Ariadne principles with two components: (1) FP training and (2) FP-patient interview. Outcomes: MAI score, health services use, quality of life (Euroqol 5D-5L), pharmacotherapy and adherence to treatment (Morisky-Green, Haynes-Sackett), and clinical and socio-demographic variables. Statistical analysis: primary outcome is the difference in MAI score between T0 and T1 and corresponding 95% confidence interval. Adjustment for confounding factors will be performed by multilevel analysis. All analyses will be carried out in accordance with the intention-to-treat principle. Discussion: It is essential to provide evidence concerning interventions on PC patients with polypharmacy and multimorbidity, conducted in the context of routine clinical practice, and involving young-old patients with significant potential for preventing negative health outcomes. Trial registration: Clinicaltrials.gov, NCT02866799Publisher PDFPeer reviewe
Higher COVID-19 pneumonia risk associated with anti-IFN-α than with anti-IFN-ω auto-Abs in children
We found that 19 (10.4%) of 183 unvaccinated children hospitalized for COVID-19 pneumonia had autoantibodies (auto-Abs) neutralizing type I IFNs (IFN-alpha 2 in 10 patients: IFN-alpha 2 only in three, IFN-alpha 2 plus IFN-omega in five, and IFN-alpha 2, IFN-omega plus IFN-beta in two; IFN-omega only in nine patients). Seven children (3.8%) had Abs neutralizing at least 10 ng/ml of one IFN, whereas the other 12 (6.6%) had Abs neutralizing only 100 pg/ml. The auto-Abs neutralized both unglycosylated and glycosylated IFNs. We also detected auto-Abs neutralizing 100 pg/ml IFN-alpha 2 in 4 of 2,267 uninfected children (0.2%) and auto-Abs neutralizing IFN-omega in 45 children (2%). The odds ratios (ORs) for life-threatening COVID-19 pneumonia were, therefore, higher for auto-Abs neutralizing IFN-alpha 2 only (OR [95% CI] = 67.6 [5.7-9,196.6]) than for auto-Abs neutralizing IFN-. only (OR [95% CI] = 2.6 [1.2-5.3]). ORs were also higher for auto-Abs neutralizing high concentrations (OR [95% CI] = 12.9 [4.6-35.9]) than for those neutralizing low concentrations (OR [95% CI] = 5.5 [3.1-9.6]) of IFN-omega and/or IFN-alpha 2
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality