The \mu-Calculus Alternation Hierarchy Collapses over Structures with Restricted Connectivity

It is known that the alternation hierarchy of least and greatest fixpoint operators in the mu-calculus is strict. However, the strictness of the alternation hierarchy does not necessarily carry over when considering restricted classes of structures. A prominent instance is the class of infinite words over which the alternation-free fragment is already as expressive as the full mu-calculus. Our current understanding of when and why the mu-calculus alternation hierarchy is not strict is limited. This paper makes progress in answering these questions by showing that the alternation hierarchy of the mu-calculus collapses to the alternation-free fragment over some classes of structures, including infinite nested words and finite graphs with feedback vertex sets of a bounded size. Common to these classes is that the connectivity between the components in a structure from such a class is restricted in the sense that the removal of certain vertices from the structure's graph decomposes it into graphs in which all paths are of finite length. Our collapse results are obtained in an automata-theoretic setting. They subsume, generalize, and strengthen several prior results on the expressivity of the mu-calculus over restricted classes of structures.Comment: In Proceedings GandALF 2012, arXiv:1210.202

On a Conditional Cauchy-type Functional Equation Involving Powers

We solve the functional equation f(x^m + y) = f(x)^m + f(y) in the realm of polynomials with integer coefficients

The Spanish Long-term Care System. ENEPRI Research Report No. 88, 15 June 2010

Launched in January 2009, ANCIEN is a research project that runs for a 44-month period and involves 20 partners from EU member states. The project principally concerns the future of long-term care (LTC) for the elderly in Europe and addresses two questions in particular: 1) How will need, demand, supply and use of LTC develop? 2) How do different systems of LTC perform? This case study on Spain is part of the first stage in the project aimed at collecting the basic data and necessary information to portray long-term care in each country of the EU. It will be followed by analysis and projections of future scenarios on long-term care needs, use, quality assurance and system performance. State-of-the-art demographic, epidemiologic and econometric modelling will be used to interpret and project needs, supply and use of long-term care over future time periods for different LTC systems

Association between chronic irritability and depressive symptoms in children and adolescents.

Association between chronic irritability and depressive symptoms in children and adolescents. Busto-Garrido, M.; Gutierrez-Castillo, D; Navas- Gonzalez, JR; Gutierrez-Bedmar, M; Gutierrez-Casares, JR; Martin-Lunar, MT; Rodríguez-Rosado, A; Pena-Andreu, JM. European Psychiatry 415(2017) 5221.Chronic irritability is the most frequently reported symptom in child and adolescent depression. The association of both has been linked with high rates of chronicity, comorbility and impairment. Objectives To study the association between chronic irritability and depressive symptoms in children and adolescents. Methods We have studied 857 participants recruited from the only Child and Adolescent Mental Health Clinic in a catchment area of 122968 people under 18 (2004-2010). A sample of 677 participants (57 controls and 620 patients) was included to carry out a cross-sectional study. Chronic irritability was measured by a Visual Analog Scale (VAS irritability) -scored from 0 to 10-, and depressive symptoms by the Children's Depression Inventory (CDI). The participants were categorized into controls and patients, and according to their chronic irritability (≤4 [I],5 [II] and ≥6 [III]). The mean of CDI score was calculated for each of the groups, adjusted by sex and age, and analyzed by ANCOVA. Results The following means were obtained from the controls: 13,71 (group I), 9,82 (group II) and 17,45 (group III). Regarding to the patients: 13,92 (group I), 11,54 (group II) and 15,64 (group III). A quadratic association (p <0,0015) was found between VAS irritability score and CDI score. Conclussions There is not a lineal association between chronic irritability and depressive symptoms in children and adolescent. High rates of depressive symptoms were associated both with high and low rates of irritability. Several questions remain unexplained about the status of irritability in psychiatry as Stringaris group has been pointed out. Disclosure statement I have no potential conflict of interest to discloseUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The Limited Effect of Graphic Elements in Video and Augmented Reality on Children’s Listening Comprehension

There is currently significant interest in the use of instructional strategies in learning environments thanks to the emergence of new multimedia systems that combine text, audio, graphics and video, such as augmented reality (AR). In this light, this study compares the effectiveness of AR and video for listening comprehension tasks. The sample consisted of thirty-two elementary school students with different reading comprehension. Firstly, the experience, instructions and objectives were introduced to all the students. Next, they were divided into two groups to perform activities—one group performed an activity involving watching an Educational Video Story of the Laika dog and her Space Journey available by mobile devices app Blue Planet Tales, while the other performed an activity involving the use of AR, whose contents of the same history were visualized by means of the app Augment Sales. Once the activities were completed participants answered a comprehension test. Results (p = 0.180) indicate there are no meaningful differences between the lesson format and test performance. But there are differences between the participants of the AR group according to their reading comprehension level. With respect to the time taken to perform the comprehension test, there is no significant difference between the two groups but there is a difference between participants with a high and low level of comprehension. To conclude SUS (System Usability Scale) questionnaire was used to establish the measure usability for the AR app on a smartphone. An average score of 77.5 out of 100 was obtained in this questionnaire, which indicates that the app has fairly good user-centered design

Bond risk premia and the return forecasting factor

The return forecasting factor is a linear combination of forward rates that seems to predict 1-year excess bond returns of bond of all maturities better than traditional measures obtained from the yield curve. If this single factor actually captures all the relevant fluctuations in bond risk premia, then it should also summarize all the economically relevant variations in excess returns considering different holding periods. We find that it does not. We conclude that including the return forecasting factor as the main driver of risk premia in a term structure model, as has been suggested, is not supported by the data.Fil: Gutierrez, Agustin. University of Chicago; Estados UnidosFil: Hevia, Constantino. Universidad Torcuato Di Tella. Departamento de Economía; ArgentinaFil: Sola, Martin. Universidad Torcuato Di Tella. Departamento de Economía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Analysis of a wingtip vortex using Higher Order Dynamical Mode Decomposition

Wingtip vortices are a key element to take into account in the design of any aerial vehicle and the planning of takeoff and landing operations on large-scale airports. In this project, we study the wingtip vortex generated by a wing model in a controlled environment. Specifically, the flow velocity field measured in the wake of a NACA0012 model is analyzed using Higher Order Dynamical Mode Decomposition (HODMD) [1]. That velocity field was obtained using the PIV technique in a towing tank at University of Málaga at a moderate Reynolds number of 40,000. By using HODMD we were able to extract the modes that capture the dissipation of the vortex and characterize its temporal decay. These modes are crucial for the analysis of any element designed to decrease the vortex intensity. These devices, active and passive, are vital in any modern aeronautical application.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech