69 research outputs found

    Do sexist mothers change more diapers? Ambivalent sexism, maternal gatekeeping and the division of childcare

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    This study examined the role of ambivalent sexist ideologies in the division of childcare responsibilities. It proposed maternal gatekeeping as a mediator through which hostile sexist attitudes toward men and women facilitate gendered division of childcare. A sample of 207 mothers with at least one child aged 6 years or younger completed extensive questionnaires. As hypothesized, the mother’s hostile sexist attitudes toward men and women were positively related to maternal gatekeeping tendencies. Gatekeeping, in turn, was related to the mother’s greater time investment in childcare and greater share of childcare tasks relative to the father. Finally, hostile sexist attitudes toward men and women had an indirect effect on the mother’s hours of care and relative share of childcare tasks, mediated though maternal gatekeeping. The findings underscore the importance of investigating the mechanisms through which sexist ideologies are translated into daily behaviors that help maintain a gendered social structure. They may be utilized to inform parenting interventions aimed at increasing collaborative family work and fathers’ participation

    An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems

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    New information on the lethal and sublethal effects of neonicotinoids and fipronil on organisms is presented in this review, complementing the previous WIA in 2015. The high toxicity of these systemic insecticides to invertebrates has been confirmed and expanded to include more species and compounds. Most of the recent research has focused on bees and the sublethal and ecological impacts these insecticides have on pollinators. Toxic effects on other invertebrate taxa also covered predatory and parasitoid natural enemies and aquatic arthropods. Little, while not much new information has been gathered on soil organisms. The impact on marine coastal ecosystems is still largely uncharted. The chronic lethality of neonicotinoids to insects and crustaceans, and the strengthened evidence that these chemicals also impair the immune system and reproduction, highlights the dangers of this particular insecticidal classneonicotinoids and fipronil. , withContinued large scale – mostly prophylactic – use of these persistent organochlorine pesticides has the potential to greatly decreasecompletely eliminate populations of arthropods in both terrestrial and aquatic environments. Sublethal effects on fish, reptiles, frogs, birds and mammals are also reported, showing a better understanding of the mechanisms of toxicity of these insecticides in vertebrates, and their deleterious impacts on growth, reproduction and neurobehaviour of most of the species tested. This review concludes with a summary of impacts on the ecosystem services and functioning, particularly on pollination, soil biota and aquatic invertebrate communities, thus reinforcing the previous WIA conclusions (van der Sluijs et al. 2015)

    European Vegetation Archive (EVA): An integrated database of European vegetation plots

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    © 2016 International Association for Vegetation Science. The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and regional vegetation- plot databases on a single software platform. Data storage in EVA does not affect on-going independent development of the contributing databases, which remain the property of the data contributors. EVA uses a prototype of the database management software TURBOVEG 3 developed for joint management of multiple databases that use different species lists. This is facilitated by the SynBioSys Taxon Database, a system of taxon names and concepts used in the individual European databases and their corresponding names on a unified list of European flora. TURBOVEG 3 also includes procedures for handling data requests, selections and provisions according to the approved EVA Data Property and Governance Rules. By 30 June 2015, 61 databases from all European regions have joined EVA, contributing in total 1 027 376 vegetation plots, 82% of them with geographic coordinates, from 57 countries. EVA provides a unique data source for large-scale analyses of European vegetation diversity both for fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database

    Spectral analysis of the direct sum Hamiltonian operators

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    In this paper we investigate the deciency indices theory and the selfad-joint and nonselfadjoint (dissipative, accumulative) extensions of the minimal symmetric direct sum Hamiltonian operators. In particular using the equivalence of the Lax-Phillips scattering matrix and the Sz.-Nagy-Foias characteristic function, we prove that all root (eigen and associated) vectors of the maximal dissipative extensions of the minimal symmetric direct sum Hamiltonian operators are complete in the Hilbert spaces.Keywords: Hamiltonian system, dissipative operator, characteristic function, scattering matrix, completeness theore

    Torque and variable stiffness control for antagonistically driven pneumatic muscle actuators via a stable force feedback controller

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    Due to copyright restrictions, the access to the full text of this article is only available via subscription.This paper describes a novel controller that is capable of simultaneously controlling torque and variable stiffness in real-time, for actuators with antagonistically driven pneumatic artificial muscles (PAMs). To this end, two contributions are presented: i) A stable force feedback controller that can cope with inherent PAM nonlinearities is synthesized using the dissipativity theory, for each PAM unit. ii) On top of this force feedback controller, a mathematical formulation is developed to compute reference force inputs that correspond to desired joint torque and joint stiffness inputs, concerning both agonist and antagonist PAMs. This strategy enables us to introduce real-time sensory feedback; torque and stiffness control is addressed by means of PAM force feedback control with guaranteed stability. To validate the proposed control scheme, a series of experiments were conducted on an experimental setup. As the result, the controller exhibited favorable torque and stiffness tracking in real-time, demonstrating that it could meet the performance criteria to power exoskeleton systems.Mext Kakenhi ; SRPBS from Mext/Amed, ImPACT Program of Council for Science, Technology and Innovation ; Development of Medical Devices and Systems for Advanced Medical Service

    Learning to exploit passive compliance for energy-efficient gait generation on a compliant humanoid

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    Due to copyright restrictions, the access to the full text of this article is only available via subscription.Modern humanoid robots include not only active compliance but also passive compliance. Apart from improved safety and dependability, availability of passive elements, such as springs, opens up new possibilities for improving the energy efficiency. With this in mind, this paper addresses the challenging open problem of exploiting the passive compliance for the purpose of energy efficient humanoid walking. To this end, we develop a method comprising two parts: an optimization part that finds an optimal vertical center-of-mass trajectory, and a walking pattern generator part that uses this trajectory to produce a dynamically-balanced gait. For the optimization part, we propose a reinforcement learning approach that dynamically evolves the policy parametrization during the learning process. By gradually increasing the representational power of the policy parametrization, it manages to find better policies in a faster and computationally efficient way. For the walking generator part, we develop a variable-center-of-mass-height ZMP-based bipedal walking pattern generator. The method is tested in real-world experiments with the bipedal robot COMAN and achieves a significant 18% reduction in the electric energy consumption by learning to efficiently use the passive compliance of the robot

    Variable ankle stiffness improves balance control: experiments on a bipedal exoskeleton

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    Due to copyright restrictions, the access to the full text of this article is only available via subscription.This paper proposes a real-time balance control technique that can be implemented to bipedal robots (exoskeletons, humanoids) whose ankle joints are powered via variable physical stiffness actuators. To achieve active balancing, an abstracted biped model, torsional spring-loaded flywheel, is utilized to capture approximated angular momentum and physical stiffness, which are of importance in postural balancing. In particular, this model enables us to describe the mathematical relation between zero moment point (ZMP) and physical stiffness. The exploitation of variable physical stiffness leads to the following contributions: 1) Variable physical stiffness property is embodied in a legged robot control task, for the first time in the literature to the authors' knowledge. 2) Through experimental studies conducted with our bipedal exoskeleton, the advantages of variable physical stiffness strategy are demonstrated with respect to the optimal constant stiffness strategy. The results indicate that the variable stiffness strategy provides more favorable results in terms of external disturbance dissipation, mechanical power reduction, and ZMP/center of mass position regulation.Strategic Research Program for Brain Science of Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan ; New Energy and Industrial Technology Development Organization (NEDO) ; ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) Ministry of Internal Affairs and Communications entitled "Novel and innovative R&D making use of brain structures" ; JST-SICP ; MIC-SCOPE ; JSPS-MIZS: Japan-Slovenia Research Cooperative Progra
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