201 research outputs found

    Synchronization in discrete-time networks with general pairwise coupling

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    We consider complete synchronization of identical maps coupled through a general interaction function and in a general network topology where the edges may be directed and may carry both positive and negative weights. We define mixed transverse exponents and derive sufficient conditions for local complete synchronization. The general non-diffusive coupling scheme can lead to new synchronous behavior, in networks of identical units, that cannot be produced by single units in isolation. In particular, we show that synchronous chaos can emerge in networks of simple units. Conversely, in networks of chaotic units simple synchronous dynamics can emerge; that is, chaos can be suppressed through synchrony

    The EUHPID Health Development Model for the classification of public health indicators

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    The European Community Health Promotion Indicator Development Model has been developed as the basis for establishing a European set of indicators for monitoring health promotion interventions. This paper offers the model more generally as a common frame of reference for broader public health practice and indicator development. The model builds around the physical, mental and social health of individuals and shows how health develops by interaction between individual and environmental health determinants. It demonstrates that health development can be analysed from a salutogenic and a pathogenic perspective and explains how the differing starting points of different intervention approaches such as health promotion and health care are related to these two perspectives. Finally, a classification system for pathogenic and salutogenic public health outcome indicators is derived from the model and has been applied to the current core list of the European Community Health Indicator system. The model and its application highlight the need for systematic salutogenic indicator development in the field of public health and for strengthening the health promotion perspective in the futur

    A systematic review of study results reported for the evaluation of robotic rollators from the perspective of users

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    © 2017 Informa UK Limited, trading as Taylor & Francis Group. Purpose: To evaluate the effectiveness and perception of robotic rollators (RRs) from the perspective of users. Methods: Studies identified in a previous systematic review published on 2016 on the methodology of studies evaluating RRs by the user perspective were re-screened for eligibility based on the following inclusion criteria: evaluation of the human–robot interaction from the user perspective, use of standardized outcome measurements, and quantitative presentation of study results. Results: Seventeen studies were eligible for inclusion. Due to the clinical and methodological heterogeneity across studies, a narrative synthesis of study results was conducted. We found conflicting results concerning the effectiveness of the robotic functionalities of the RRs. Only a few studies reported superior user performance or reduced physical demands with the RRs compared to unassisted conditions or conventional assistive mobility devices; however, without providing statistical evidence. The user perception of the RRs was found to be generally positive. Conclusions: There is still no sufficient evidence on the effectiveness of RRs from the user perspective. More well-designed, high-quality studies with adequate study populations, larger sample sizes, appropriate assessment strategies with outcomes specifically tailored to the robotic functionalities, and statistical analyses of results are required to evaluate RRs at a higher level of evidence.Implications for Rehabilitation RRs cover intelligent functionalities that focus on gait assistance, obstacle avoidance, navigation assistance, sit-to-stand transfer, body weight support or fall prevention. The evaluation from the user perspective is essential to ensure that RRs effectively address users’ needs, requirements and preferences. The evidence on the effectiveness of RRs is severely hampered by the low methodological quality of most of the available studies. RRs seem generally to be perceived as positive by the users. There is very limited evidence on the effectiveness and benefits of RRs compared to conventional assistive mobility devices. Further research with high methodological quality needs to be conducted to reach more robust conclusions about the effectiveness of RRs

    Improving Melanoma Classification by Integrating Genetic and Morphologic Features

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    Boris Bastian and colleagues present a refined morphological classification of primary melanomas that can be used to improve existing melanoma classifications by defining genetically homogeneous subgroups

    A miniaturized endocardial electromagnetic energy harvester for leadless cardiac pacemakers

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    Life expectancy of contemporary cardiac pacemakers is limited due to the use of an internal primary battery. Repeated device replacement interventions are necessary, which leads to an elevated risk for patients and an increase of health care costs. The aim of our study is to investigate the feasibility of powering an endocardial pacemaker by converting a minimal amount of the heart's kinetic energy into electric energy. The intrinsic cardiac muscle activity makes it an ideal candidate as continuous source of energy for endocardial pacemakers. For this reason, we developed a prototype able to generate enough power to supply a pacing circuit at different heart rates. The prototype consists of a mass imbalance that drives an electromagnetic generator while oscillating. We developed a mathematical model to estimate the amount of energy harvested from the right ventricle. Finally, the implemented prototype was successfully tested during in-vitro and in-vivo experiments

    Stability of remission rates in a 3-year follow-up of naturalistic treated depressed inpatients

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    Background Remission is a common outcome of short-term trials and the main goal of acute and longterm treatment. The longitudinal stability of remission has rarely been investigated under naturalistic treatment conditions. Methods Naturalistic multisite follow-up study. Three-year symptomatic long-term outcome of initially hospitalized tertiary care patients (N = 784) with major depressive episodes. Remission rates as well as the switch rates between remission and non-remission were reported. Results After one, two and three years 62 %, 59 % and 69 % of the observed patients met criteria for remission. During the follow-up 88 % of all patients achieved remission. 36 % of maintained remission from discharge to 3-years, 12 % of all patients never reached remission and 52 % percent showed a fluctuating course switching from remission to non-remission and vice versa. There was considerable transition between remission and non-remission. For example, from discharge to 1 year, from 1 to 2, and from 2 to 3 years 25 %, 21 % and 11 % lost remission. Conclusion Cumulative outcome rates are encouraging. Absolute rates at predefined endpoints as well as the fluctuations between these outcomes reflect the variable and chronic nature of major depression

    Perforin deficiency attenuates collagen-induced arthritis

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    Collagen-induced arthritis (CIA), an approved animal model for rheumatoid arthritis, is thought to be a T cell-dependent disease. There is evidence that CD8(+ )T cells are a major subset controlling the pathogenesis of CIA. They probably contribute to certain features of disease, namely tissue destruction and synovial hyperplasia. In this study we examined the role of perforin (pfp), a key molecule of the cytotoxic death pathway that is expressed mainly in CD8(+ )T cells, for the pathogenesis of CIA. We generated DBA/1J mice suffering from mutations of the pfp molecule, DBA/1J-pfp(-/-), and studied their susceptibility to arthritis. As a result, pfp-deficient mice showed a reduced incidence (DBA/1J-pfp(+/+), 64%; DBA/1J-pfp(-/-), 54%), a slightly delayed onset (onset of disease: DBA/1J-pfp(+/+), 53 ± 3.6; DBA/1J-pfp(-/-), 59 ± 4.9 (mean ± SEM), and milder form of the disease (maximum disease score: DBA/1J-pfp(+/+), 7.3 ± 1.1; DBA/1J-pfp(-/-), 3.4 ± 1.4 (mean ± SEM); P < 0.05). Concomitantly, peripheral T cell proliferation in response to the specific antigen bovine collagen II was increased in pfp(-/- )mice compared with pfp(+/+ )mice, arguing for an impaired killing of autoreactive T cells caused by pfp deficiency. Thus, pfp-mediated cytotoxicity is involved in the initiation of tissue damage in arthritis, but pfp-independent cytotoxic death pathways might also contribute to CIA
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