645 research outputs found
Vortices on demand in multicomponent Bose-Einstein condensates
We present a simple mechanism to produce vortices at any desired spatial
locations in harmonically trapped Bose-Einstein condensates (BEC) with
multicomponent spin states coupled to external transverse and axial magnetic
fields. The vortices appear at the spatial points where the spin-transverse
field interaction vanishes and, depending on the multipolar magnetic field
order, the vortices can acquire different predictable topological charges. We
explicitly demonstrate our findings, both numerically and analytically, by
analyzing a 2D BEC via the Gross-Pitaevskii equation for atomic systems with
either two or three internal states. We further show that, by an spontaneous
symmetry breaking mechanism, vortices can appear in any spin component, unless
symmetry is externally broken at the outset by an axial field. We suggest that
this scenario may be tested using an ultracold gas of Rb occupying all
three states in an optical trap.Comment: 11 pages, 9 figures, (Accepted in PRA
Hamiltonian Noether theorem for gauge systems and two time physics
The Noether theorem for Hamiltonian constrained systems is revisited. In
particular, our review presents a novel method to show that the gauge
transformations are generated by the conserved quantities associated with the
first class constraints. We apply our results to the relativistic point
particle, to the Friedberg et al. model and, with special emphasis, to two time
physics.Comment: 20 pages, Latex, references added, the "massless" sense of (87) is
clarifie
Electrodynamics a la Horava
We study an electrodynamics consistent with anisotropic transformations of
space-time with an arbitrary dynamic exponent . The equations of motion and
conserved quantities are explicitly obtained. We show that the propagator of
this theory can be regarded as a quantum correction to the usual propagator.
Moreover we obtain that both the momentum and angular momentum are not
modified, but their conservation laws do change. We also show that in this
theory the speed of light and the electric charge are modified with . The
magnetic monopole in this electrodynamics and its duality transformations are
also investigated. For that we found that there exists a dual electrodynamics,
with higher derivatives in the electric field, invariant under the same
anisotropic transformations.Comment: 14 pages, no figures, version to appears in Mod. Phys. Lett.
A motivational interview program for cardiac rehabilitation after acute myocardial infarction: study protocol of a randomized controlled trial in primary healthcare
Cardiac rehabilitation after acute myocardial infarction permits recovery of the heart function and enables secondary prevention programs in which changes in lifestyle habits are crucial. Cardiac rehabilitation often takes place in hospitals without coordination with primary healthcare and is not focused on individual patient preferences and goals, which is the core of the motivational interview. The objective of this study was to evaluate the efficacy of a cardiac rehabilitation program with a motivational interview in patients discharged from hospital after acute myocardial infarction.A randomized, non-pharmacological clinical trial in six primary healthcare centers in Barcelona (Spain) will assess whether a tailored cardiac rehabilitation program consisting of four motivational interviews and visits with family physicians, primary healthcare nurses and a cardiologist, coordinated with the reference hospital, results in better cardiac rehabilitation than standard care. A minimum sample of 284 participants requiring cardiac rehabilitation after acute myocardial infarction will be randomized to a cardiac rehabilitation group with a motivational interview program or to standard primary healthcare. The main outcome will be physical function measured by the six-minute walk test, and the secondary outcome will be the effectiveness of secondary prevention: a composite outcome comprising control of blood pressure, cholesterol, diabetes mellitus, smoking and body weight. Results will be evaluated at 1,3 and 6 months.This is the first clinical trial to study the impact of a new primary healthcare cardiac rehabilitation program with motivational interviews for patients discharged from hospital after myocardial infarction. Changes in lifestyles and habits after myocardial infarction are a core element of secondary prevention and require patient-centered care strategies such as motivational interviews. Therefore, this study could clarify the impact of this approach on health indicators, such as functional capacity.ClinicalTriasl.gov NCT05285969 registered on March 18, 2022.© 2022. The Author(s)
Habitat quality affects the condition of Luciobarbus sclateri in the Guadiamar River (SW Iberian Peninsula): Effects of disturbances by the toxic spill of the AznalcĂłllar mine
This study analyzes the somatic condition of southern Iberian barbel Luciobarbus sclateri (GĂŒnther, 1868) in the Guadiamar River (SW Iberian Peninsula). This river was seriously affected by a toxic spill of about 4 million cubic meters of acidic water and 2 million cubic meters of mud rich in heavy metals. Once the spill removal works concluded, sites affected and unaffected by the accident were sampled to study its effects on the fish fauna. The ecological variables registered were related to water quality, physical state of reaches, ecological quality, resources exploited by fish, and potential intra-specific interactions. From an initial 15 ecological variables, seasonal water flow and pH explained most of the variation in barbel condition. This study shows that the Guadiamar River, 56 months after the accident, is still undergoing a recovery process where, beyond ecological variables, proximity to the affected area is the most influential factor for fish condition. © 2012 Springer Science+Business Media B.V
RegeneraciĂłn de campus para la creaciĂłn de un laboratorio vivo de sostenibilidad ("living lab") en el Campus de Excelencia Internacional de Moncloa
La Universidad PolitĂ©cnica de Madrid (UPM) a travĂ©s de su Centro de InnovaciĂłn en TecnologĂa para el Desarrollo Humano (itdUPM) estĂĄ propiciando la generaciĂłn de conciencia, conocimiento y soluciones innovadoras que contribuyen al cumplimiento de los Objetivos de Desarrollo Sostenible a travĂ©s de un edificio que sirve como laboratorio de prueba para nuevas tecnologĂas verdes y como plataforma de ideaciĂłn colaborativa y activaciĂłn social
Micromechanical Properties of Injection-Molded StarchâWood Particle Composites
The micromechanical properties of injection molded starchâwood particle composites were investigated as a function of particle content and humidity conditions.
The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness
of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence
were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density
and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starchâwood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that
the wood in the starch composites did not prevent water loss from the samples.Peer reviewe
Studies of new Higgs boson interactions through nonresonant HH production in the bÂŻbγγ fnal state in pp collisions at âs = 13 TeV with the ATLAS detector
A search for nonresonant Higgs boson pair production in the b
¯bγγ fnal state
is performed using 140 fbâ1 of proton-proton collisions at a centre-of-mass energy of 13 TeV
recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes
and expands upon the previous nonresonant ATLAS results in this fnal state based on the
same data sample. The analysis strategy is optimised to probe anomalous values not only of
the Higgs (H) boson self-coupling modifer Îșλ but also of the quartic HHV V (V = W, Z)
coupling modifer Îș2V . No signifcant excess above the expected background from Standard
Model processes is observed. An observed upper limit ”HH < 4.0 is set at 95% confdence
level on the Higgs boson pair production cross-section normalised to its Standard Model
prediction. The 95% confdence intervals for the coupling modifers are â1.4 < Îșλ < 6.9 and
â0.5 < Îș2V < 2.7, assuming all other Higgs boson couplings except the one under study are
fxed to the Standard Model predictions. The results are interpreted in the Standard Model
efective feld theory and Higgs efective feld theory frameworks in terms of constraints on
the couplings of anomalous Higgs boson (self-)interactions
Epidemiology of intra-abdominal infection and sepsis in critically ill patients: âAbSeSâ, a multinational observational cohort study and ESICM Trials Group Project
Purpose: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). Methods: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. Results: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. Conclusion: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection
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