158 research outputs found

    Semiclassical quantification of some two degree of freedom potentials: a Differential Galois approach

    Full text link
    In this work we explain the relevance of the Differential Galois Theory in the semiclassical (or WKB) quantification of some two degree of freedom potentials. The key point is that the semiclassical path integral quantification around a particular solution depends on the variational equation around that solution: a very well-known object in dynamical systems and variational calculus. Then, as the variational equation is a linear ordinary differential system, it is possible to apply the Differential Galois Theory to study its solvability in closed form. We obtain closed form solutions for the semiclassical quantum fluctuations around constant velocity solutions for some systems like the classical Hermite/Verhulst, Bessel, Legendre, and Lam\'e potentials. We remark that some of the systems studied are not integrable, in the Liouville-Arnold sense

    Metodologías complementarias de aprendizaje para la adquisición de competencias en la formación de especialistas y actividades profesionales confiables

    Get PDF
    El aprendizaje del residente se realiza a través del trabajo que desarrolla en diferentes contextos laborales como: la planta del hospital, el quirófano, el centro de salud, la participación en congresos o en comisiones, etc. Aun así, este desempeño tiene que complementarse con metodologías que conlleven actividades específicas para desarrollar aquellas competencias que no se pueden trabajar de forma planificada y explícita en el día a día como el pensamiento crítico, el trabajo cooperativo, la gestión de las emociones, etc. Más allá de las clásicas sesiones clínicas de casos o bibliográficas, existen otras metodologías activas dirigidas a favorecer estos aprendizajes para alcanzar una formación integral, como el aprendizaje basado en problemas, el método de caso y de proyectos, los incidentes críticos, la gamificación, los juegos de rol o el libro del residente. Destacamos las competencias que cada una de ellas ayudan a adquirir. Dedicamos un apartado a las actividades profesionales confiables (APROC) o entrustable professional activities (EPAs), por tratarse de un enfoque metodológico operativo que facilita la puesta en práctica de la formación y evaluación basada en competencias a través de tareas o actividades complejas. La combinación de metodologías complementarias con las actividades clínicas completa el mapa para adquirir las competencias requeridas en los programas de formación especializada. De este modo, se pretende ayudar al formador a planificar la formación del residente de acuerdo a su perfil competencial. The resident's learning is developed through the work in different settings such as: the hospital ward, the primary health center, the operating room, the participation in congresses or in committees, etc. Even so, this performance has to be complemented with methodologies that involve specific activities to develop those competencies that cannot be worked on a day-to-day basis (critical thinking, cooperative work, emotion management, etc.). We present other methodologies aimed to achieve those competencies, such as problem-based learning, the projects method, the case method, and the critical incidents, gamification, role-playing games or the resident's logbook, highlighting the competencies that each of them help to acquire. We dedicate a section to entrustable professional activities (EPAs), an operational methodological approach that facilitates the implementation of competency-based medical education and evaluation through clinical activities. The combination of complementary methodologies with clinical activities completes the map to acquire the competencies required in specialized training and guide the tutor in order to plan the training of the specialist

    Unravelling the mechanisms that determine the uptake and metabolism of magnetic single and multicore nanoparticles in a Xenopus laevis model.

    Get PDF
    Multicore superparamagnetic nanoparticles have been proposed as ideal tools for some biomedical applications because of their high magnetic moment per particle, high specific surface area and long term colloidal stability. Through controlled aggregation and packing of magnetic cores it is possible to obtain not only single-core but also multicore and hollow spheres with internal voids. In this work, we compare toxicological properties of single and multicore nanoparticles. Both types of particles showed moderate in vitro toxicity (MTT assay) tested in Hep G2 (human hepatocellular carcinoma) and Caco-2 (human colorectal adenocarcinoma) cells. The influence of surface chemistry in their biological behavior was also studied after functionalization with O,O′-bis(2-aminoethyl) PEG (2000 Da). For the first time, these nanoparticles were evaluated in a Xenopus laevis model studying their whole organism toxicity and their impact upon iron metabolism. The degree of activation of the metabolic pathway depends on the size and surface charge of the nanoparticles which determine their uptake. The results also highlight the potential of Xenopus laevis model bridging the gap between in vitro cell-based assays and rodent models for toxicity assessment to develop effective nanoparticles for biomedical applications

    Relationship between cognition and age at onset of first-episode psychosis: comparative study between adolescents, young adults, and adults

    Get PDF
    Psychotic disorders typically manifest from late adolescence to early adulthood, and an earlier onset might be associated with greater symptom severity and a worse long-term prognosis. This study aimed to compare the cognitive characteristics of patients with first-episode psychosis (FEP) by their age at onset. We included 298 patients diagnosed with FEP and classified them as having an early onset (EOS), youth onset (YOS), or adult onset (AOS) based on age limits of = 25 years (N = 116), respectively. Socio-demographic and clinical variables included age at baseline, gender, socio-economic status, antipsychotic medication, DSM-IV diagnoses assessed by clinical semi-structured interview, psychotic symptom severity, and age at onset. Neuropsychological assessment included six cognitive domains: premorbid intelligence, working memory, processing speed, verbal memory, sustained attention, and executive functioning. The EOS group had lower scores than the YOS or AOS groups in global cognition, executive functioning, and sustained attention. Although the scores in the YOS group were intermediate to those in the EOS and AOS groups for most cognitive factors, no statistically significant differences were detected between the YOS and AOS groups. Age at onset results in specific patterns of cognitive interference. Of note, impairment appears to be greater with EOS samples than with either YOS or AOS samples. A longitudinal study with a larger sample size is needed to confirm our findings

    Obstetric complications and clinical presentation in first episode of psychosis

    Get PDF
    Objective: Psychotic disorders exhibit a complex aetiology that combines genetic and environmental factors. Among the latter, obstetric complications (OCs) have been widely studied as risk factors, but it is not yet well understood how OCs relate to the heterogeneous presentations of psychotic disorders. We assessed the clinical phenotypes of individuals with a first episode of psychosis (FEP) in relation to the presence of OCs. Methods: Two-hundred seventy-seven patients with an FEP were assessed for OCs using the Lewis–Murray scale, with data stratified into three subscales depending on the timing and the characteristics of the obstetric event, namely: complications of pregnancy, abnormal foetal growth and development and difficulties in delivery. We also considered other two groups: any complications during the pregnancy period and all OCs taken altogether. Patients were clinically evaluated with the Positive and Negative Syndrome Scale for schizophrenia. Results: Total OCs and difficulties in delivery were related to more severe psychopathology, and this remained significant after co-varying for age, sex, traumatic experiences, antipsychotic dosage and cannabis use. Conclusions: Our results highlight the relevance of OCs for the clinical presentation of psychosis. Describing the timing of the OCs is essential in understanding the heterogeneity of the clinical presentation

    The CARMENES search for exoplanets around M dwarfs. Two temperate Earth-mass planet candidates around Teegarden’s Star

    Get PDF
    Context.Teegarden’s Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0 V),the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES.Aims.As part of the CARMENES search for exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements of Teegarden’sStar and analysed them for planetary signals.Methods.We find periodic variability in the radial velocities of Teegarden’s Star. We also studied photometric measurements to rule out stellarbrightness variations mimicking planetary signals.Results.We find evidence for two planet candidates, each with 1.1M⊕minimum mass, orbiting at periods of 4.91 and 11.4 d, respectively. Noevidence for planetary transits could be found in archival and follow-up photometry. Small photometric variability is suggestive of slow rotationand old age.Conclusions.The two planets are among the lowest-mass planets discovered so far, and they are the first Earth-mass planets around an ultra-cooldwarf for which the masses have been determined using radial velocities.We thank the referee Rodrigo Díaz for a careful review andhelpful comments. M.Z. acknowledges support from the Deutsche Forschungs-gemeinschaft under DFG RE 1664/12-1 and Research Unit FOR2544 “BluePlanets around Red Stars”, project no. RE 1664/14-1. CARMENES isan instrument for the Centro Astronómico Hispano-Alemán de Calar Alto(CAHA, Almería, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de InvestigacionesCientíficas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, LandessternwarteKönigstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen,Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg,Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astro-biología and Centro Astronómico Hispano-Alemán), with additional contribu-tions by the Spanish Ministry of Economy, the German Science Foundationthrough the Major Research Instrumentation Programme and DFG ResearchUnit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, thestates of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía.Based on data from the CARMENES data archive at CAB (INTA-CSIC). Thisarticle is based on observations made with the MuSCAT2 instrument, devel-oped by ABC, at Telescopio Carlos Sánchez operated on the island of Tener-ife by the IAC in the Spanish Observatorio del Teide. Data were partly col-lected with the 150-cm and 90-cm telescopes at the Sierra Nevada Observa-tory (SNO) operated by the Instituto de Astrofísica de Andalucía (IAA-CSIC).Data were partly obtained with the MONET/South telescope of the MOnitoringNEtwork of Telescopes, funded by the Alfried Krupp von Bohlen und HalbachFoundation, Essen, and operated by the Georg-August-Universität Göttingen,the McDonald Observatory of the University of Texas at Austin, and the SouthAfrican Astronomical Observatory. We acknowledge financial support from theSpanish Agencia Estatal de Investigación of the Ministerio de Ciencia, Inno-vación y Universidades and the European FEDER/ERF funds through projectsAYA2015-69350-C3-2-P, AYA2016-79425-C3-1/2/3-P, AYA2018-84089, BES-2017-080769, BES-2017-082610, ESP2015-65712-C5-5-R, ESP2016-80435-C2-1/2-R, ESP2017-87143-R, ESP2017-87676-2-2, ESP2017-87676-C5-1/2/5-R, FPU15/01476, RYC-2012-09913, the Centre of Excellence ”Severo Ochoa”and ”María de Maeztu” awards to the Instituto de Astrofísica de Canarias (SEV-2015-0548), Instituto de Astrofísica de Andalucía (SEV-2017-0709), and Cen-tro de Astrobiología (MDM-2017-0737), the Generalitat de Catalunya throughCERCA programme”, the Deutsches Zentrum für Luft- und Raumfahrt throughgrants 50OW0204 and 50OO1501, the European Research Council through grant694513, the Italian Ministero dell’instruzione, dell’università de della ricerca andUniversità degli Studi di Roma Tor Vergata through FFABR 2017 and “Mis-sion: Sustainability 2016”, the UK Science and Technology Facilities Council through grant ST/P000592/1, the Israel Science Foundation through grant848/16, the Chilean CONICYT-FONDECYT through grant 3180405, the Mexi-can CONACYT through grant CVU 448248, the JSPS KAKENHI through grantsJP18H01265 and 18H05439, and the JST PRESTO through grant JPMJPR1775

    Ideal cardiovascular health and inflammation in European adolescents: The HELENA study

    Get PDF
    Background and aims Inflammation plays a key role in atherosclerosis and this process seems to appear in childhood. The ideal cardiovascular health index (ICHI) has been inversely related to atherosclerotic plaque in adults. However, evidence regarding inflammation and ICHI in adolescents is scarce. The aim is to assess the association between ICHI and inflammation in European adolescents. Methods and results As many as 543 adolescents (251 boys and 292 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional multi-center study including 9 European countries, were measured. C-reactive protein (CRP), complement factors C3 and C4, leptin and white blood cell counts were used to compute an inflammatory score. Multilevel linear models and multilevel logistic regression were used to assess the association between ICHI and inflammation controlling by covariates. Higher ICHI was associated with a lower inflammatory score, as well as with several individual components, both in boys and girls (p < 0.01). In addition, adolescents with at least 4 ideal components of the ICHI had significantly lower inflammatory score and lower levels of the study biomarkers, except CRP. Finally, the multilevel logistic regression showed that for every unit increase in the ICHI, the probability of having an inflammatory profile decreased by 28.1% in girls. Conclusion Results from this study suggest that a better ICHI is associated with a lower inflammatory profile already in adolescence. Improving these health behaviors, and health factors included in the ICHI, could play an important role in CVD prevention

    Role of age and comorbidities in mortality of patients with infective endocarditis

    Get PDF
    Purpose: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. Methods: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015. Patients were stratified into three age groups:<65 years, 65 to 80 years, and = 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. Results: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 = 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients =80 years who underwent surgery were significantly lower compared with other age groups (14.3%, 65 years; 20.5%, 65-79 years; 31.3%, =80 years). In-hospital mortality was lower in the <65-year group (20.3%, <65 years;30.1%, 65-79 years;34.7%, =80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%, =80 years; p = 0.003).Independent predictors of mortality were age = 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI = 3 (HR:1.62; 95% CI:1.39–1.88), and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared, the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. Conclusion: There were no differences in the clinical presentation of IE between the groups. Age = 80 years, high comorbidity (measured by CCI), and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group
    corecore