11 research outputs found

    Small-scale properties of the KPZ equation and dynamical symmetry breaking

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    A functional integral technique is used to study the ultraviolet or short distance properties of the Kardar-Parisi-Zhang (KPZ) equation with white Gaussian noise. We apply this technique to calculate the one-loop effective potential for the KPZ equation. The effective potential is (at least) one-loop ultraviolet renormalizable in 1, 2, and 3 space dimensions, but non-renormalizable in 4 or higher space dimensions. This potential is intimately related to the probability distribution function (PDF) for the spacetime averaged field. For the restricted class of field configurations considered here, the KPZ equation exhibits dynamical symmetry breaking (DSB) via an analog of the Coleman-Weinberg mechanism in 1 and 2 space dimensions, but not in 3 space dimensions.Comment: V2 --- 6 pages, LaTeX 209, ReV_TeX 3.2. Title changed, presentation clarified, additional discussion added, references updated. No significant changes in physics conclusions. This version to appear in Physics Letters

    Renormalization Group Analysis of a Quivering String Model of Posture Control

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    Scaling concepts and renormalization group (RG) methods are applied to a simple linear model of human posture control consisting of a trembling or quivering string subject to damping and restoring forces. The string is driven by uncorrelated white Gaussian noise intended to model the corrections of the physiological control system. We find that adding a weak quadratic nonlinearity to the posture control model opens up a rich and complicated phase space (representing the dynamics) with various non-trivial fixed points and basins of attraction. The transition from diffusive to saturated regimes of the linear model is understood as a crossover phenomenon, and the robustness of the linear model with respect to weak non-linearities is confirmed. Correlations in posture fluctuations are obtained in both the time and space domain. There is an attractive fixed point identified with falling. The scaling of the correlations in the front-back displacement, which can be measured in the laboratory, is predicted for both the large-separation (along the string) and long-time regimes of posture control.Comment: 20 pages, 13 figures, RevTeX, accepted for publication in PR

    Desarrollo de herramientas metodológicas para incorporar contenidos de ciencia al aula y su valoración económica

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    La ciencia y la tecnología juegan un papel fundamental en nuestra sociedad. En este sentido, la ciudadanía parece necesitar unos conocimientos básicos que le permitan responder de manera autónoma a multitud de situaciones, tanto a nivel personal como social (Kolstø et al., 2006). Este requisito, conocido en la literatura como alfabetización científica, lleva siendo uno de los objetivos de la educación en las últimas décadas (Hodson, 2003; Feinstein, 2011). Sin embargo, parece que su consecución presenta algunos problemas. Una de las causas de estas dificultades parece ser la falta de conexión entre los contenidos que se trabajan en las clases y el día a día del ciudadano. Respecto a esto, una solución ampliamente citada en la literatura es contextualizar el aprendizaje, relacionando los contenidos trabajados en clase con escenarios cotidianos y familiares para el alumnado (Clegg & Kolodner, 2014). El proyecto pretendía que nuestros estudiantes llevasen a cabo un análisis de los contextos con contenidos científico-económicos y promovieran su utilización en el aula y en su futuro profesional. Es decir, formar a nuestros profesionales para que pudieran detectar e incorporar entre sus competencias la capacidad de conectar lo aprendido en las asignaturas con las necesidades sociales. En concreto, el proyecto tenía, en base a los problemas detectados en la percepción de la ciencia y en la formación de los ciudadanos, dos grandes tipos de objetivos: Objetivos relacionados con la percepción de los conocimientos científico-tecnológicos y su valoración económica (Ezquerra, Fernández-Sánchez, Cabezas, 2013; Ezquerra, Fernandez-Sanchez, 2014; Ezquerra, Fernandez-Sanchez, Magaña, 2015; 2016; Ezquerra, Fernandez-Sanchez, Magaña & Mingo, 2017): • Identificar en qué situaciones los ciudadanos, en su vida cotidiana, están en presencia de contenidos científicos o tecnológicos. • Determinar de qué modo llegan al ciudadano estos contenidos, con qué intensidad, cómo son propuestos, cómo son percibidos... • Analizar el modo en que podemos otorgar a estos contenidos una valoración económica. Objetivos educativos que se integran dentro de las asignaturas: • Analizar las correspondencias entre los currículos oficiales y los contenidos presentes en el entorno del ciudadano (Ezquerra, Fernandez-Sanchez, Magaña Ramos, 2015; Ezquerra y Magaña, 2016). • Introducir a los estudiantes en una propuesta de aprendizaje basada en la indagación (Rivero et al., 2013; Ezquerra, De Juanas, Martín del Pozo, 2015). • Valorar las estrategias y competencias de los futuros docentes para vincular sus conocimientos con la realidad circundante (De Juanas et al., 2012). • Analizar las actividades que los estudiantes propongan para identificar los contenidos de ciencia y estudiar su valoración económica

    Efficacy of clozapine versus standard treatment in adult individuals with intellectual disability and treatment-resistant psychosis (CLOZAID): study protocol of a multicenter randomized clinical trial

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    BackgroundIntellectual disability (ID) affects approximately 1% of the worldwide population and individuals with ID have a higher comorbidity with mental illness, and specifically psychotic disorders. Unfortunately, among individuals with ID, limited research has been conducted since ID individuals are usually excluded from mental illness epidemiological studies and clinical trials. Here we perform a clinical trial to investigate the effectiveness of clozapine in the treatment of resistant psychosis in individuals with ID. The article highlights the complexity of diagnosing and treating psychopathological alterations associated with ID and advocates for more rigorous research in this field.MethodsA Phase IIB, open-label, randomized, multicenter clinical trial (NCT04529226) is currently ongoing to assess the efficacy of oral clozapine in individuals diagnosed with ID and suffering from treatment-resistant psychosis. We aim to recruit one-hundred and fourteen individuals (N=114) with ID and resistant psychosis, who will be randomized to TAU (treatment as usual) and treatment-with-clozapine conditions. As secondary outcomes, changes in other clinical scales (PANSS and SANS) and the improvement in functionality, assessed through changes in the Euro-QoL-5D-5L were assessed. The main outcome variables will be analyzed using generalized linear mixed models (GLMM), assessing the effects of status variable (TAU vs. Clozapine), time, and the interaction between them.DiscussionThe treatment of resistant psychosis among ID individuals must be directed by empirically supported research. CLOZAID clinical trial may provide relevant information about clinical guidelines to optimally treat adults with ID and treatment-resistant psychosis and the benefits and risks of an early use of clozapine in this underrepresented population in clinical trials.Trial registrationClinicaltrials.gov: NCT04529226. EudraCT: 2020-000091-37

    Optimising a Microgrid System by Deep Reinforcement Learning Techniques

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    The deployment of microgrids could be fostered by control systems that do not require very complex modelling, calibration, prediction and/or optimisation processes. This paper explores the application of Reinforcement Learning (RL) techniques for the operation of a microgrid. The implemented Deep Q-Network (DQN) can learn an optimal policy for the operation of the elements of an isolated microgrid, based on the interaction agent-environment when particular operation actions are taken in the microgrid components. In order to facilitate the scaling-up of this solution, the algorithm relies exclusively on historical data from past events, and therefore it does not require forecasts of the demand or the renewable generation. The objective is to minimise the cost of operating the microgrid, including the penalty of non-served power. This paper analyses the effect of considering different definitions for the state of the system by expanding the set of variables that define it. The obtained results are very satisfactory as it can be concluded by their comparison with the perfect-information optimal operation computed with a traditional optimisation model, and with a Naive model

    Oral administration of heat-inactivated Mycobacterium bovis reduces the response of farmed red deer to avian and bovine tuberculin

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    Orally delivered mycobacterial antigens may not sensitize the immunized animals causing a positive tuberculin skin test response. As the first step to address this critical issue, we characterized the response of farmed red deer (Cervus elaphus) to orally delivered heat-inactivated Mycobacterium bovis. Thirty-two adult red deer hinds from a farm known to be free of tuberculosis (TB) were randomly assigned to two different treatment groups, immunized (n = 24) and control (n = 8). Immunized hinds were dosed orally with 2 ml of PBS containing 6 × 10 heat-inactivated M. bovis. The mean skin test response of immunized deer to both avian purified protein derivative (aPPD) and bovine PPD (bPPD) was consistently lower in immunized than in control hinds. One year after immunization, immunized hinds had a significant reduction in the skin test response to aPPD and in the ELISA antibody levels against both aPPD and bPPD (24-36% reduction; P < 0.05). By contrast, no significant change was observed in the skin test response to phytohaemagglutinin, or in the ELISA antibody levels against the M. bovis specific antigen MPB70. The mRNA levels for C3, IFN-γ and IL-1β and serum protein levels for IFN-γ and IL-1β did not vary between immunized and control deer. However, serum C3 protein levels were significantly higher (P = 0.001) in immunized than in control deer six months after immunization. These results confirm that oral heat-inactivated M. bovis does not sensitize farmed red deer and therefore does not cause false-positive responses in the tuberculin skin test. The absence of sensitization in orally immunized deer opens the possibility of testing the vaccine in deer and possibly other ruminants without the risk of causing false-positive reactions in TB-tests. This study also provided the first evidence that orally-delivered inactivated mycobacterial antigens elicit some kind of immune response in a ruminant.Research funding is acknowledged to Plan Nacional grant AGL2014-56305 (MINECO, Spain and FEDER) and the EU FP7 grants WildTBvac #613779 and ANTIGONE #278976. VL was supported by a grant from Universidad Autónoma de Sinaloa, Mexico.Peer Reviewe

    Learning by educating: e-Service learning experience of oral health promotion

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    La metodología utilizada durante todo el proyecto fue el recurso en línea, dada la situación de crisis sanitaria debido al COVID-19. Internet fue el medio principal y único para llevar a cabo todas las actividades, desde el reclutamiento y la preparación de los estudiantes hasta la implementación del servicio y su evaluación. La realización de un e-ApS es posible y ofrece las oportunidades necesarias para que los alumnos desarrollen su valor de ciudadanía inclusiva, digna y democrática, al igual que cuando el proyecto se realiza de manera presencial.Due to the health crisis due to COVID-19, the methodology used in the project was the online resource. The Internet was the medium for carrying out all activities, from the recruitment and preparation of students to the implementation of the service and its assessment. Carrying out an e-ApS is possible and it offers the necessary opportunities for students to develop their value of inclusive, respectful and democratic citizenship, just as when the project is carried out in person.Oficina Universitaria de Aprendizaje-Servicio UCMDepto. de Especialidades Clínicas OdontológicasFac. de OdontologíaTRUEsubmitte

    Incidence of severe critical events in paediatric anaesthesia (APRICOT): a prospective multicentre observational study in 261 hospitals in Europe

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    Background Little is known about the incidence of severe critical events in children undergoing general anaesthesia in Europe. We aimed to identify the incidence, nature, and outcome of severe critical events in children undergoing anaesthesia, and the associated potential risk factors. Methods The APRICOT study was a prospective observational multicentre cohort study of children from birth to 15 years of age undergoing elective or urgent anaesthesia for diagnostic or surgical procedures. Children were eligible for inclusion during a 2-week period determined prospectively by each centre. There were 261 participating centres across 33 European countries. The primary endpoint was the occurence of perioperative severe critical events requiring immediate intervention. A severe critical event was defined as the occurrence of respiratory, cardiac, allergic, or neurological complications requiring immediate intervention and that led (or could have led) to major disability or death. This study is registered with ClinicalTrials.gov, number NCT01878760. Findings Between April 1, 2014, and Jan 31, 2015, 31â127 anaesthetic procedures in 30â874 children with a mean age of 6·35 years (SD 4·50) were included. The incidence of perioperative severe critical events was 5·2% (95% CI 5·0â5·5) with an incidence of respiratory critical events of 3·1% (2·9â3·3). Cardiovascular instability occurred in 1·9% (1·7â2·1), with an immediate poor outcome in 5·4% (3·7â7·5) of these cases. The all-cause 30-day in-hospital mortality rate was 10 in 10â000. This was independent of type of anaesthesia. Age (relative risk 0·88, 95% CI 0·86â0·90; p<0·0001), medical history, and physical condition (1·60, 1·40â1·82; p<0·0001) were the major risk factors for a serious critical event. Multivariate analysis revealed evidence for the beneficial effect of years of experience of the most senior anaesthesia team member (0·99, 0·981â0·997; p<0·0048 for respiratory critical events, and 0·98, 0·97â0·99; p=0·0039 for cardiovascular critical events), rather than the type of health institution or providers. Interpretation This study highlights a relatively high rate of severe critical events during the anaesthesia management of children for surgical or diagnostic procedures in Europe, and a large variability in the practice of paediatric anaesthesia. These findings are substantial enough to warrant attention from national, regional, and specialist societies to target education of anaesthesiologists and their teams and implement strategies for quality improvement in paediatric anaesthesia. Funding European Society of Anaesthesiology
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