Detecting the direction of a signal on high-dimensional spheres: Non-null and Le Cam optimality results

We consider one of the most important problems in directional statistics, namely the problem of testing the null hypothesis that the spike direction $\theta$ of a Fisher-von Mises-Langevin distribution on the $p$-dimensional unit hypersphere is equal to a given direction $\theta_0$. After a reduction through invariance arguments, we derive local asymptotic normality (LAN) results in a general high-dimensional framework where the dimension $p_n$ goes to infinity at an arbitrary rate with the sample size $n$, and where the concentration $\kappa_n$ behaves in a completely free way with $n$, which offers a spectrum of problems ranging from arbitrarily easy to arbitrarily challenging ones. We identify various asymptotic regimes, depending on the convergence/divergence properties of $(\kappa_n)$, that yield different contiguity rates and different limiting experiments. In each regime, we derive Le Cam optimal tests under specified $\kappa_n$ and we compute, from the Le Cam third lemma, asymptotic powers of the classical Watson test under contiguous alternatives. We further establish LAN results with respect to both spike direction and concentration, which allows us to discuss optimality also under unspecified $\kappa_n$. To investigate the non-null behavior of the Watson test outside the parametric framework above, we derive its local asymptotic powers through martingale CLTs in the broader, semiparametric, model of rotationally symmetric distributions. A Monte Carlo study shows that the finite-sample behaviors of the various tests remarkably agree with our asymptotic results.Comment: 47 pages, 4 figure

Exploring the socio-ecological factors behind the (in)active lifestyles of Spanish post-bariatric surgery patients

Purpose: Physical activity (PA) is considered essential for the treatment of morbid obesity and the optimization of bariatric surgery outcomes. The objective of this article was to identify the facilitators and barriers that bariatric patients perceived to do PA one year after finishing a PA programme for the promotion of a long-term active lifestyle. This objective was addressed from a socio-ecological and qualitative perspective. Methods: Nine patients (eight women and one man), aged between 31 and 59 years, participated in semi-structured interviews directly following the PA programme and one year after it. A content analysis was carried out to analyze the qualitative data. Results: Weight loss, improvement of physical fitness, perceived competence, and enjoyment were the main facilitators of PA. Complexes related to skin folds, osteoarthritis, perceived unfavourable weather conditions, lack of social support and economic resources, long workdays, lack of specific PA programmes, and other passive leisure preferences were the main barriers to participate in PA. Conclusions: Results highlight the important interplay between personal, social environmental, and physical environmental factors to explain (in)active behaviours of bariatric patients. The findings of this article could be useful for future research and interventions aimed at promoting PA in bariatric patients

Internet use by older adults with bipolar disorder: international survey results

Background: The world population is aging and the number of older adults with bipolar disorder is increasing. Digital technologies are viewed as a framework to improve care of older adults with bipolar disorder. This analysis quantifies Internet use by older adults with bipolar disorder as part of a larger survey project about information seeking. Methods: A paper-based survey about information seeking by patients with bipolar disorder was developed and translated into 12 languages. The survey was anonymous and completed between March 2014 and January 2016 by 1222 patients in 17 countries. All patients were diagnosed by a psychiatrist. General estimating equations were used to account for correlated data. Results: Overall, 47% of older adults (age 60 years or older) used the Internet versus 87% of younger adults (less than 60 years). More education and having symptoms that interfered with regular activities increased the odds of using the Internet, while being age 60 years or older decreased the odds. Data from 187 older adults and 1021 younger adults were included in the analysis excluding missing values. Conclusions: Older adults with bipolar disorder use the Internet much less frequently than younger adults. Many older adults do not use the Internet, and technology tools are suitable for some but not all older adults. As more health services are only available online, and more digital tools are developed, there is concern about growing health disparities based on age. Mental health experts should participate in determining the appropriate role for digital tools for older adults with bipolar disorder.We acknowledge support by the Open Access Publication Funds of the SLUB/TU Dresden (Grant No. IN-1502335)

Collaborative e-learning through drag & share in synchronous shared workspaces

e-Learning platforms allow users to collaborate with one other. Moodle, as one of the main e-Learning platforms, provides tools to perform collaborative tasks. With these tasks, students are able to share documents and information. The means provided by Moodle are not enough to perform some collaborative tasks, such as sharing documents in real-time. In this scenario users must be aware of what is happening in the system effectively. We propose the use of Drag Share within Moodle, a collaborative tool that allows users to synchronously share resources in real-time. Through this tool, teachers are able to easily provide a shared workspace for students and be able to create groups. With such a tool, students can share all kind of resources and be aware of what is going on in the system in which they are participating and of what they are doing. All these features use standard technologies, such as HTML5

Multirate control with incomplete information over Profibus-DP network

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Systems Science on 2014, available online:http://www.tandfonline.com/10.1080/00207721.2013.844286When a process ¿eld bus-decentralized peripherals (Pro¿bus-DP) network is used in an industrial environment, a deterministic behaviour is usually claimed. However, due to some concerns such as bandwidth limitations, lack of synchronisation among different clocks and existence of time-varying delays, a more complex problem must be faced. This problem implies the transmission of irregular and, even, random sequences of incomplete information. The main consequence of this issue is the appearance of different sampling periods at different network devices. In this paper, this aspect is checked by means of a detailed Pro¿bus-DP timescale study. In addition, in order to deal with the different periods, a delay-dependent dual-rate proportional-integral-derivative control is introduced. 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The Architecture of the Neural System for Control of a Mobile Robot

Building autonomous mobile robots has been a primary aim of robotics and artificial intelligence. Artificial neural networks are capable of performing the different aspecis of autonomous drmng, such as collision-free motions, avoiding obstacles, mapping and planning of path. This paper describes the global architecture of the neural system for autonomous control of a mobile robot. Such neural system has the ability for self-training and self-organizing. The purpose of this paper is to present the key ideas and approaches underlying our research in this area

Bim-mediated apoptosis and PD-1/PD-L1 pathway impair reactivity of PD1+/CD127- HCV-specific CD8+ cells targeting the virus in chronic hepatitis C virus infection

26 p.PD-1 molecule promotes anergy and IL-7 receptor (CD127) induces an anti-apoptotic effect on T cells. Correlation between PD-1/CD127 phenotype and hepatitis C virus (HCV)-specific CD8+ cell reactivity in resolved infection (RI) after treatment and persistent HCV-infection (PI) was analysed. Directly ex vivo, PD-1 and CD127 expression on HCV-specific CD8+ cells displayed a positive and negative correlation, respectively with viraemia. Proliferation after stimulation on PD-1/CD127+ cells from RI cases was preserved, while it was impaired on PD-1+/CD127 cells from PI patients. PD1+/CD127+ population was observed in PI, and these maintained expansion ability but they did not target the virus. Frequency of PI cases with HCV-specific CD8+ cell proliferation increased after anti-PD-L1 and anti-apoptotic treatment. Bim expression on HCV-specific CD8+ cells from PI patients was enhanced. In conclusion, during chronic HCV infection non-reactive HCV-specific CD8+ cells targeting the virus are PD-1+/CD127/Bim+ and, blocking apoptosis and PD-1/PD-L1 pathway on them enhances in vitro reactivity.Junta de Comunidades de Castilla-La ManchaFundación de Investigación Médica Mutua MadrileñaInstituto de Salud Carlos IIIAsociación de Hepatología Translaciona