272 research outputs found

    Differential game theory for versatile physical human-robot interaction

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    The last decades have seen a surge of robots working in contact with humans. However, until now these contact robots have made little use of the opportunities offered by physical interaction and lack a systematic methodology to produce versatile behaviours. Here, we develop an interactive robot controller able to understand the control strategy of the human user and react optimally to their movements. We demonstrate that combining an observer with a differential game theory controller can induce a stable interaction between the two partners, precisely identify each other’s control law, and allow them to successfully perform the task with minimum effort. Simulations and experiments with human subjects demonstrate these properties and illustrate how this controller can induce different representative interaction strategies

    Distribution of causes of maternal mortality among different socio-demographic groups in Ghana; a descriptive study

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    BACKGROUND: Ghana's maternal mortality ratio remains high despite efforts made to meet Millennium Development Goal 5. A number of studies have been conducted on maternal mortality in Ghana; however, little is known about how the causes of maternal mortality are distributed in different socio-demographic subgroups. Therefore the aim of this study was to assess and analyse the causes of maternal mortality according to socio-demographic factors in Ghana.METHODS: The causes of maternal deaths were assessed with respect to age, educational level, rural/urban residence status and marital status. Data from a five year retrospective survey was used. The data was obtained from Ghana Maternal Health Survey 2007 acquired from the database of Ghana Statistical Service. A total of 605 maternal deaths within the age group 12-49 years were analysed using frequency tables, cross-tabulations and logistic regression.RESULTS: Haemorrhage was the highest cause of maternal mortality (22.8%). Married women had a significantly higher risk of dying from haemorrhage, compared with single women (adjusted OR = 2.7, 95%CI = 1.2-5.7). On the contrary, married women showed a significantly reduced risk of dying from abortion compared to single women (adjusted OR = 0.2, 95%CI = 0.1-0.4). Women aged 35-39 years had a significantly higher risk of dying from haemorrhage (aOR 2.6, 95%CI = 1.4-4.9), whereas they were at a lower risk of dying from abortion (aOR 0.3, 95% CI = 0.1-0.7) compared to their younger counterparts. The risk of maternal death from infectious diseases decreased with increasing maternal age, whereas the risk of dying from miscellaneous causes increased with increasing age.CONCLUSIONS: The study shows evidence of variations in the causes of maternal mortality among different socio-demographic subgroups in Ghana that should not be overlooked. It is therefore recommended that interventions aimed at combating the high maternal mortality in Ghana should be both cause-specific as well as target-specific

    Subjective response to antipsychotic treatment and compliance in schizophrenia. A naturalistic study comparing olanzapine, risperidone and haloperidol (EFESO Study)

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    BACKGROUND: In order to compare the effectiveness of different antipsychotic drugs in the treatment of schizophrenia it is very important to evaluate subjective response and compliance in patient cohorts treated according to routine clinical practice. METHOD: Outpatients with schizophrenia entered this prospective, naturalistic study when they received a new prescription for an antipsychotic drug. Treatment assignment was based on purely clinical criteria, as the study did not include any experimental intervention. Patients treated with olanzapine, risperidone or haloperidol were included in the analysis. Subjective response was measured using the 10-item version of the Drug Attitude Inventory (DAI-10), and treatment compliance was measured using a physician-rated 4 point categorical scale. RESULTS: A total of 2128 patients initiated treatment (as monotherapy) with olanzapine, 417 with risperidone, and 112 with haloperidol. Olanzapine-treated patients had significantly higher DAI-10 scores and significantly better treatment compliance compared to both risperidone- and haloperidol-treated patients. Risperidone-treated patients had a significantly higher DAI-10 score compared to haloperidol-treated patients. CONCLUSION: Subjective response and compliance were superior in olanzapine-treated patients, compared to patients treated with risperidone and haloperidol, in routine clinical practice. Differences in subjective response were explained largely, but not completely, by differences in incidence of EPS

    Glutamate receptor-like channels are essential for chemotaxis and reproduction in mosses

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    The deposited article version is a "Accelerated Article Preview" provided by Nature Publishing Group, and it contains attached the supplementary materials within the pdf.». This publication hasn't any creative commons license associated.Glutamate receptors are well characterized channels that mediate cell-to-cell communication during neurotransmission in animals. Nevertheless, information regarding their functional role in organisms without nervous systems is still limited. In plants, Glutamate Receptor-like (GLR) genes have been implicated in defence against pathogens, reproduction, control of stomata aperture and light signal transduction(1-5). However, the numerous GLR genes present in angiosperm genomes (20 to 70)(6) has prevented the observation of strong phenotypes in loss-of-function mutants. Here, we show that in the moss Physcomitrella patens, a basal land plant, mutation of GLR genes cause sperm failure in targeting the female reproductive organs. In addition, we show that GLR genes encode non-selective Ca(2+) permeable channels that can regulate cytoplasmic Ca(2+) and are needed to induce the expression of a BELL1-like transcription factor essential for zygote development. Our work reveals novel functions for GLRs in sperm chemotaxis and transcriptional regulation. Sperm chemotaxis is essential for fertilization in both animals and early land plants like bryophytes and pteridophytes. Therefore, our results are suggestive that ionotropic glutamate receptors may have been conserved throughout plant evolution to mediate cell-to-cell communication during sexual reproduction.Phillips University; Oxford University; University of Marburg; University of Muenster; MarieCurie ITN-Plant Origins grant: (FP7-PEOPLE-ITN-2008); FCT grants: (BEX-BCM/0376/2012; PTDC/BIA-PLA/4018/2012); NSF-US grant: (MCB 1616437/2016).info:eu-repo/semantics/acceptedVersio

    Measurement of the top quark mass using the matrix element technique in dilepton final states

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    We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7  fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84  GeV

    Rydberg-Stark deceleration of atoms and molecules

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    Getting Acquainted with Kant

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    My question here concerns whether Kant claims that experience has nonconceptual content, or whether, on his view, experience is essentially conceptual. However there is a sense in which this debate concerning the content of intuition is ill-conceived. Part of this has to do with the terms in which the debate is set, and part to do with confusion over the connection between Kant’s own views and contemporary concerns in epistemology and the philosophy of mind. However, I think much of the substance of the debate concerning Kant’s views on the content of experience can be salvaged by reframing it in terms of a debate about the dependence relations, if any, that exist between different cognitive capacities. Below, in Section 2, I clarify the notion of ‘content’ I take to be at stake in the interpretive debate. Section 3 presents reasons for thinking that intuition cannot have content in the relevant sense. I then argue, in Section 4, that the debate be reframed in terms of dependence. We should distinguish between Intellectualism, according to which all objective representation (understood in a particular way) depends on acts of synthesis by the intellect, and Sensibilism, according to which at least some forms of objective representation are independent of any such acts (or the capacity for such acts). Finally, in Section 5, I further elucidate the cognitive role of intuition. I articulate a challenge which Kant understands alethic modal considerations to present for achieving cognition, and argue that a version of Sensibilism that construes intuition as a form of acquaintance is better positioned to answer this challenge than Intellectualism

    Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

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    T2K reports its first measurements of the parameters governing the disappearance of ν-μ in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν-μ beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν-μ survival probability is expected to be minimal. Using a data set corresponding to 4.01×1020 protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin2(θ-23)=0.45 and |Δm-322|=2.51×10-3 eV2 with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10-3 eV2, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the νμ disappearance parameters measured by T2K

    A reporting format for leaf-level gas exchange data and metadata

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    Leaf-level gas exchange data support the mechanistic understanding of plant fluxes of carbon and water. These fluxes inform our understanding of ecosystem function, are an important constraint on parameterization of terrestrial biosphere models, are necessary to understand the response of plants to global environmental change, and are integral to efforts to improve crop production. Collection of these data using gas analyzers can be both technically challenging and time consuming, and individual studies generally focus on a small range of species, restricted time periods, or limited geographic regions. The high value of these data is exemplified by the many publications that reuse and synthesize gas exchange data, however the lack of metadata and data reporting conventions make full and efficient use of these data difficult. Here we propose a reporting format for leaf-level gas exchange data and metadata to provide guidance to data contributors on how to store data in repositories to maximize their discoverability, facilitate their efficient reuse, and add value to individual datasets. For data users, the reporting format will better allow data repositories to optimize data search and extraction, and more readily integrate similar data into harmonized synthesis products. The reporting format specifies data table variable naming and unit conventions, as well as metadata characterizing experimental conditions and protocols. For common data types that were the focus of this initial version of the reporting format, i.e., survey measurements, dark respiration, carbon dioxide and light response curves, and parameters derived from those measurements, we took a further step of defining required additional data and metadata that would maximize the potential reuse of those data types. To aid data contributors and the development of data ingest tools by data repositories we provided a translation table comparing the outputs of common gas exchange instruments. Extensive consultation with data collectors, data users, instrument manufacturers, and data scientists was undertaken in order to ensure that the reporting format met community needs. The reporting format presented here is intended to form a foundation for future development that will incorporate additional data types and variables as gas exchange systems and measurement approaches advance in the future. The reporting format is published in the U.S. Department of Energy's ESS-DIVE data repository, with documentation and future development efforts being maintained in a version control system
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