123 research outputs found

    A dual larynx motor networks hypothesis

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    Humans are vocal modulators par excellence. This ability is supported in part by the dual representation of the laryngeal muscles in the motor cortex. Movement, however, is not the product of motor cortex alone but of a broader motor network. This network consists of brain regions that contain somatotopic maps that parallel the organization in motor cortex. We therefore present a novel hypothesis that the dual laryngeal representation is repeated throughout the broader motor network. In support of the hypothesis, we review existing literature that demonstrates the existence of network-wide somatotopy and present initial evidence for the hypothesis' plausibility. Understanding how this uniquely human phenotype in motor cortex interacts with broader brain networks is an important step toward understanding how humans evolved the ability to speak. We further suggest that this system may provide a means to study how individual components of the nervous system evolved within the context of neuronal networks. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part I)’

    Foliar lead uptake by lettuce exposed to atmospheric fallouts

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    Metal uptake by plants occurs by soil−root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 ± 50 mg Pb kg−1 (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination

    Lessons learnt from ORGAP Project – planning, implementation and evaluation of Action Plans for Organic Food and Farming

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    Within the EU funded project ORGAP, a toolbox was developed for the evaluation of the European as well as national action plans for organic food and farming. Also recommendations and a resource manual for policy makers and stakeholders were developed. These were based on the analysis of national Organic Action Plans as well as stakeholder and expert consultation. The analysis showed that several EU member states have emphasised the need to balance supply-push policies with more market-focused demand-pull policies. An integrated approach is required and this has been to differing degrees through the formulation of multi-functional Organic Action Plans (OAPs), which also adress the dual roles of organic farming (from a policy perspective) to provide public goods and satisfy consumer demand. Eight Organic Action Plans, reviewed in the ORGAP project, vary with regard to the elaboration process, targets, objectives and the emphasis of measures on certain areas (e.g. market versus environment orientation). This variation is due to quite different political and socio-economic framework conditions for organic farming in these countries. It revealed that the weaknesses identified in the status quo analysis of the organic sector have only partly been translated to the targets and measures included in the action plan documents. Definition of the priorities for development of organic agriculture must be agreed by all relevant stakeholders. The priorities, and hence the programmes, will depend on correct analysis of the issues (and conflicts) that need to be addressed and clear objectives with measurable outcomes (for effective evaluation). For more information on the project, on the practical project manual and the evaluation toolbox for Organic Action Plans see project website www.orgap.or

    temporary implementation and testing of a confocal sr ÎŒxrf system for bone analysis at the x ray fluorescence beamline at elettra

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    Abstract The confocal ÎŒ XRF spectrometer of Atominstitut (ATI) was transported and set up at the X-ray Fluorescence beamline at Elettra - Sincrotrone Trieste. It was successfully adjusted to the incoming beam (9.2 keV). Test measurements on a free-standing Cu wire were performed to determine the size of the focused micro-beam (non-confocal mode, 56 × 35 ÎŒ m 2 ) and the size of the confocal volume (confocal mode, 41 × 24 × 34 ÎŒ m 2 ) for the Cu–K α emission. In order to test the setup's capabilities, two areas on different human bone samples were measured in confocal scanning mode. For one of the samples the comparison with a previous ÎŒ XRF measurement, obtained with a low power X-ray tube in the lab, is presented

    Where spirituality and religion meet gender and sexuality::Towards a research agenda for intersectional marketing theory

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    During a roundtable discussion at the 2022 GENMAC Conference, a group of researchers specializing in religiosity and spiritual consumption, using examples from their own fieldwork, reflected on how (i) researchers’ subject positioning—including their gender and sexuality—shape fieldwork in multifaceted manners; (ii) investigations of religious/spiritual fields would benefit from a heightened sensitivity to issues of gender and sexuality; and (iii) greater sensitivity to aspects of religion and/or spirituality can help gender and sexuality scholars better understand consumers and markets. Based on the above, in this commentary paper, we call for intersectional reflexivity, attention to vulnerability and discomfort during fieldwork, and critical sensitivity to the religious “context of context” during theorization. Furthermore, we argue that specific spiritual/religious imaginaries can foster new research approaches that can contribute to more nuanced fieldwork and theorization in marketing and consumer research.</p

    Interaction between a bisphosphonate, tiludronate, and biomimetic nanocrystalline apatites.

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    Bisphosphonates (BPs) are well established as successful antiresorptive agents for the prevention and treatment of bone diseases such as osteoporosis and Paget's disease. The aim of this work was to clarify the reaction mechanisms between a BP molecule, tiludronate, and the nanocrystalline apatite surface. The adsorption of tiludronate on well characterized synthetic biomimetic nanocrystalline apatites with homogeneous but different compositions and surface characteristics was investigated to determine the effect of the nanocrystalline apatite substrate on the adsorption behavior. The results show that the adsorption of tiludronate on nanocrystalline biomimetic apatite surfaces varies over a large range. The most immature apatitic samples exhibited the highest affinity and the greatest amount adsorbed at saturation. Maturation of the nanocrystals induces a decrease of these values. The amount of phosphate ion released per adsorbed BP molecule varied, depending on the nanocrystalline substrate considered. The adsorption mechanism, although associated with a release of phosphate ions, cannot be considered as a simple ion exchange process involving one or two phosphate ions on the surface. A two-step process is proposed consisting of a surface binding of BP groups to calcium ions associated with a proton release inducing the protonation of surface orthophosphate ions and their eventual solubilization

    Ion exchanges in apatites. Effects on composition and properties

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    The modification of the composition of apatites materials can be made by several processes corresponding to ion exchange reactions which can conveniently be adapted to current coatings and ceramics and are an alternative to the set up of new synthesis methods. In addition to high temperature thermal treatments, which allow to virtually replace partly or totally monovalent OH- anion of stoichiometric hydroxyapatite by any halogen ion or carbonate, aqueous processes corresponding to dissolution-reprecipitation reactions have also been proposed and used. The most interesting possibilities are however provided by aqueous ion exchange reactions involving nanocrystalline apatites. These apatites are characterised by the existence on the crystal surface of a hydrated layer of loosely bound mineral ions which can be easily exchanged in solution. This layer offers a possibility to trap mineral ions and possibly active molecules which can modify the apatite properties. Such processes are involved in mineralised tissues and could be used in biomaterials for the release of active mineral species
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