Li–Yorke chaos in nonautonomous Hopf bifurcation patterns - I

We analyze the characteristics of the global attractor of a type of dissipative nonautonomous dynamical systems in terms of the Sacker and Sell spectrum of its linear part. The model gives rise to a pattern of nonautonomous Hopf bifurcation which can be understood as a generalization of the classical autonomous one. We pay special attention to the dynamics at the bifurcation point, showing the possibility of occurrence of Li-Yorke chaos in the corresponding attractor and hence of a high degree of unpredictability.MINECO/FEDER, MTM2015-66330-PEuropean Commission, H2020-MSCA-ITN-201

Non-Atkinson perturbations of nonautonomous linear Hamiltonian systems: exponential dichotomy and nonoscillation

Producción CientíficaWe analyze the presence of exponential dichotomy (ED) and of global existence of Weyl functions $M^\pm$ for one-parametric families of finite-dimensional nonautonomous linear Hamiltonian systems defined along the orbits of a compact metric space, which are perturbed from an initial one in a direction which does not satisfy the classical Atkinson condition: either they do not have ED for any value of the parameter; or they have it for at least all the nonreal values, in which case the Weyl functions exist and are Herglotz. When the parameter varies in the real line, and if the unperturbed family satisfies the properties of exponential dichotomy and global existence of $M^+$, then these two properties persist in a neighborhood of 0 which agrees either with the whole real line or with an open negative half-line; and in this last case, the ED fails at the right end value. The properties of ED and of global existence of $M^+$ are fundamental to guarantee the solvability of classical minimization problems given by linear-quadratic control processes.MINECO/FEDER, MTM2015-66330-PEuropean Commission, H2020-MSCA-ITN-201

La intertextualidad en televisión : cine y publicidad

El presente artículo es una reflexión sobre la influencia del cine en la publicidad, concretamente del séptimo arte en los anuncios televisivos. Se aporta un análisis, no en todos sus sentidos sino en los aspectos más relevantes, para desentrañar la relación que existe entre ambas disciplinas. Dado que el objetivo es amplio y ambicioso, el estudio se centrará en un caso en particular que enlaza directamente la influencia de una película concreta en un anuncio concreto. Podríamos hacer un recorrido por todas las campañas publicitarias basadas en películas de ficción¿ desde Big, de Penny Marshall, a Náufrago, de Robert Zemeckis, La máscara, de Chuck Russell, Nosferatu, de Murnau o, más recientemente, El sexto sentido, de Night Shyamalan. En este caso partimos del concepto de intertextualidad para realizar un análisis del spot 'Cinco años' del coche Mercedes Clase C en el que se encuentran nexos con la película protagonizada por Tom Hanks en 1988, Big. El objetivo, pues, es evidenciar, mediante un análisis narrativo de ambos discursos, que realmente existe dicha intertextualidad. Los protagonistas, la música, los temas tratados, el eslogan son algunas de las claves que señalan que realmente sí existe un vínculo intencionado por parte de los creadores del anuncio de la casa Mercedes, quien una vez más mima al detalle la creatividad de sus campañas para empatizar con el público en general y con su target en particular. Hay que señalar que cuando se descubre la conexión con la película se cierra el círculo para el que fue concebido el spot y la satisfacción -por parte del espectador- y la eficacia -por parte del emisor- es mucho mayor.This article reflects about the influence of cinema in advertising, particularly of cinema in TV ads. It provides an analysis, not in all respects, but the most important aspects to unravel the relationship between the two disciplines. Since the objective is broad and ambitious, the study will focus on a particular case which directly links the influence of a particular film on a particular advertisement. We could do a tour of all advertising campaigns based on fiction movies ... Big, from Penny Marshall, Cast Away, from Robert Zemeckis, The Mask, from Chuck Russell, Nosferatu, from Murnau or, more recently, the sixth sense, from Night Shyamalan. In this case we start from the concept of intertextuality to spot analysis of the 'Five Years' Mercedes C-Class car in which there are links to the movie starring by Tom Hanks in 1988, Big. The goal, then, is to show, through a narrative analysis of both speeches, that there really is such intertextuality. The characters, music, themes, the slogan are some of the key really does show that there is a link intended by the creators of the announcement of the house Mercedes, who once again indulges in detail the creativity of their campaigns to empathize with the public in general and in particular its target. Note that when you discover the connection to the film full circle for which it was conceived the spot and the satisfaction of the viewer-and effectivenessby the issuer, is greate

Cine y publicidad . La intertextualidad en el anuncio de Mercedes clase C

Este artículo es una reflexión sobre la influencia del cine en la publicidad comercial, concretamente del séptimo arte en los spots. Y mucho más puntual, el estudio se centrará en un caso en particular: se trata del comercial ‘Cinco años’ del coche Mercedes clase C en el que se encuentran nexos con la película protagonizada por Tom Hanks, Big. El objetivo del siguiente pretende, mediante un análisis de contenido, evidenciar que realmente existe dicha intertextualidad. Los protagonistas, la música, los temas, el eslogan… son algunas de las claves que apuntan hasta este vínculo intencionado por parte de la casa Mercedes.This article is a reflection about cinema's influence on commercial advertising, specifically the cinema on spots. And much more timely, the research will be based on a particular case: it’s about Mercedes C-class' spot called 'Five years' in which we can find connections the movie starring the actor Tom Hanks, Big, in 1988. The present objective, then, is to prove, through the analysis of the content, that the above-mentioned intertextuality does exist. Main characters, music, matters and slogan… are some of the keys that show that there is really a deliberate link made by the creators of the spot

Existence of global attractor for a nonautonomous state-dependent delay differential equation of neuronal type

The analysis of the long-term behavior of the mathematical model of a neural network constitutes a suitable framework to develop new tools for the dynamical description of nonautonomous state-dependent delay equations (SDDEs). The concept of global attractor is given, and some results which establish properties ensuring its existence and providing a description of its shape, are proved. Conditions for the exponential stability of the global attractor are also studied. Some properties of comparison of solutions constitute a key in the proof of the main results, introducing methods of monotonicity in the dynamical analysis of nonautonomous SDDEs. Numerical simulations of some illustrative models show the applicability of the theory.Ministerio de Economía y Competitividad / FEDER, MTM2015-66330-PMinisterio de Ciencia, Innovación y Universidades, RTI2018-096523-B-I00European Commission, H2020-MSCA-ITN-201

Rate-induced tipping and saddle-node bifurcation for quadratic differential equations with nonautonomous asymptotic dynamics

An in-depth analysis of nonautonomous bifurcations of saddle-node type for scalar differential equations $x'=-x^2+q(t)\,x+p(t)$, where $q\colon\R\to\R$ and $p\colon\R\to\R$ are bounded and uniformly continuous, is fundamental to explain the absence or occurrence of rate-induced tipping for the differential equation $y' =(y-(2/\pi)\arctan(ct))^2+p(t)$ as the rate $c$ varies on $[0,\infty)$. A classical attractor-repeller pair, whose existence for $c=0$ is assumed, may persist for any $c>0$, or disappear for a certain critical rate $c=c_0$, giving rise to rate-induced tipping. A suitable example demonstrates that this tipping phenomenon may be reversible.Marie Skłodowska-Curie grant agreement No 643073Ministerio de Ciencia, Innovación y Universidades, RTI2018-096523-B-I00Marie Skłodowska-Curie grant agreement No 75446

Sense of coherence and substance use in Spanish adolescents. Does the effect of SOC depend on patterns of substance use in their peer group?

Los objetivos de este trabajo fueron analizar las relaciones entre el sentido de coherencia (SOC) y el consumo de sustancias en los adolescentes españoles y el potencial efecto moderador de los patrones de consumo de sustancias en el grupo de iguales en dicha relación. La muestra constaba de 5475 adolescentes españoles de 15 a 18 años, participantes en la edición 2010 del estudio Health Behaviour in School-aged Children (HBSC). Los análisis estadísticos consistieron en análisis de cluster, para identificar grupos de adolescentes según los patrones de consumo de sustancias en su grupo de iguales, y regresión logística, con el SOC y los patrones de consumo en el grupo de iguales como predictores del consumo actual de tabaco y alcohol, episodios de embriaguez alguna vez en la vida y en la actualidad. Los resultados mostraron que un fuerte SOC parecía reducir la probabilidad de consumo de tabaco y episodios de embriaguez, pero no se asoció con el consumo actual de alcohol. Además, el efecto protector del SOC estaba moderado por los patrones de consumo del grupo de iguales. En concreto, el SOC tuvo un efecto protector significativo en los adolescentes cuyo grupo de iguales mostraba un patrón de no consumo o de frecuente consumo de alcohol y episodios de embriaguez ocasionales, pero el efecto del SOC desapareció si el patrón de consumo de los iguales incluía drogas ilegales. En conclusión, el SOC tiende a actuar como un factor protector individual respecto al consumo de sustancias durante la adolescencia, pero la influencia del grupo de iguales parece moderar dicho efecto protector del SOC.The aims of this work were to analyse the relationships between sense of coherence (SOC) and substance use among Spanish adolescents and to examine the potential moderator effect of the patterns of substance use in the peer group. Sample consisted of 5475 Spanish adolescents aged 15 to 18 from the 2010 edition of the Health Behaviour in School-aged Children (HBSC) study. Statistical analysis included cluster analysis to identify groups of adolescents according to their peer group’s patterns of substance use and logistic regression with SOC and peers’ pattern of consumption as predictors of current tobacco use, current alcohol use, life-time drunkenness and current drunkenness. The results showed that a strong SOC seemed to reduce the adolescents’ likelihood of involving in tobacco use and drunkenness, but it was not associated with being a current drinker. In addition, the protective effect of SOC was moderated by peers’ patterns of substance use. Specifically, SOC had a significant protective influence in adolescents whose peer group showed either a nonconsumption pattern or a pattern of frequent alcohol use and occasional drunkenness; but the protective effect of SOC disappeared if peers showed a pattern of consumption that included illegal drugs. In conclusion, SOC tends to act as a protective personal variable with respect to substance use during adolescence, but the influence exerted by the peer group seems to moderate the aforementioned protective effect of SOC

Uniform stability and chaotic dynamics in nonhomogeneous linear dissipative scalar ordinary differential equations

Producción CientíficaThe paper analyzes the structure and the inner long-term dynamics of the invariant compact sets for the skewproduct flow induced by a family of time-dependent ordinary differential equations of nonhomogeneous linear dissipative type. The main assumptions are made on the dissipative term and on the homogeneous linear term of the equations. The rich casuistic includes the uniform stability of the invariant compact sets, as well as the presence of Li-Yorke chaos and Auslander-Yorke chaos inside the attractor.MINECO-Feder (RTI2018-098850-B-I00)Junta de Andalucía (PY18-RT-2422 y B-FQM-580-UGR20)Ministerio de Ciencia e Innovación (PID2021-125446NB-100)Universidad de Valladolid (PIP-TCESC-2020

Understanding the joint effects of family and other developmental contexts on the sense of coherence (SOC): A person-focused analysis using the Classification Tree

Using a person-focused approach, the present study sought to identify meaningful constellations of contextual factors that led to predominantly high and low levels of sense of coherence (SOC). Specifically, the contributions of the quality of parent-child relationships, teacher and classmate support, models of behaviour in the peer group, and neighbourhood assets were examined in a representative sample of Spanish adolescents aged 13 to 18 that had taken part in the 2010 edition of the study Health Behaviour in School-aged Children. The quality of parent-child relationships emerged as the main predictor of SOC for the whole sample, but the remaining factors also made significant contributions, which underlines the importance of the simultaneous analysis of the main contexts in adolescents’ lives. Additionally, the identified constellations usually included compensatory effects, so no factor should be considered to be completely determining. Interestingly, the role of support at school was different depending on contextual profiles.Ministerio de Educación AP2009-097