496 research outputs found

    Experimental Impacts into Feldspar Phenocrysts

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    Meteorite impact craters are the dominant surface feature on most terrestrial planetary bodies [1]. The extreme temperatures and pressures generated by hypervelocity impact events produce a variety of microscopic shock metamorphic effects in minerals, as well as non-exclusive shock-related features such as pervasive fracturing and brecciation.<p></p> Studies of shock effects in feldspar group minerals have been limited due to the the comparatively rapid rate at which feldspars weather, and the complexity of their microtextures which renders them difficult to study using conventional optical techniques. However, feldspars are becoming increasingly investigated for use as shock barometers due to their importance in planetary studies and meteoritics, where rocks often contain little or no quartz [e.g., 2]. This provides the motivation to examine more closely the effects of high-velocity impact of a projectile, in the method of [3], into a feldspathic target, in order to the resultant microstructural variation.<p></p&gt

    ‘It just opens up their world’: autism, empathy, and the therapeutic effects of equine interactions

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    Experiences of autism-spectrum disorder are now increasingly studied by social scientists. Human–animal relations have also become a major focus of social inquiry in recent years. Examining horse-assisted therapy for autistic spectrum disorders, this is the first paper that brings these fields together. Drawing on participant observation and interviews at a UK horse therapy Centre, this article examines how staff and the parents of riders account for the successes and limitations of equine therapy. To the respondents, horses ‘open up’ autistic children and make possible interactions that seemed impossible before. Horses were regarded as facilitating the emergence of apparently social behaviours, which included eye contact, pointing, and speech. Three key explanations emerged for therapeutic success: the sensorial, embodied experience of riding the horse; the specific movements and rhythms of the horse; and, the ‘personality’ of the horse. Equine therapy can be regarded as enabling a form of multispecies intersubjectivity, with the resonance between rider and horse seeming to make possible a new attunement between humans. Practices of equine therapy, and perceptions of its efficacy, serve in turn to attune social scientists to a version of empathy constituted through lively and sensorial interactions, as opposed to one that is restricted to particular kinds of humans

    Responsible research and innovation: A manifesto for empirical ethics?

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    In 2013 the Nuffield Council on Bioethics launched their report Novel Neurotechnologies: Intervening in the Brain. The report, which adopts the European Commission's notion of Responsible Research and Innovation, puts forward a set of priorities to guide ethical research into, and the development of, new therapeutic neurotechnologies. In this paper, we critically engage with these priorities. We argue that the Nuffield Council's priorities, and the Responsible Research and Innovation initiative as a whole, are laudable and should guide research and innovation in all areas of healthcare. However, we argue that operationalising Responsible Research and Innovation requires an in-depth understanding of the research and clinical contexts. Providing such an understanding is an important task for empirical ethics. Drawing on examples from sociology, science and technology studies, and related disciplines, we propose four avenues of social science research which can provide such an understanding. We suggest that these avenues can provide a manifesto for empirical ethics.The paper derives from a project that was funded by Wellcome Trust (Wellcome Trust Biomedical Strategic Award 086034)

    The changing brain: Neuroscience and the enduring import of everyday experience

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    Discourses of ‘neuroplasticity’ have become increasingly apparent in the neurosciences and wider society. These connect with broader narratives about the ‘changing brain’ throughout the life-course. Here, we explore their presence in the talk of a range of publics. Their presence is indicative of how novel neuroscience is accepted, or not, by our participants. In particular, we suggest that any acceptance of the science relates to their personal and/or professional experiences of change (to their own or others’ subjectivities) rather than to some intrinsic and widely-held significance of scientific concepts per se. Accordingly, we also submit that it is in part through the congruence of some neuroscientific claims to everyday experiences and perspectives that the former are rendered legible and salient. In this respect, ‘lay’ knowledge has considerable import for the wider cultural authorisation of that of ‘experts’

    Experimental Impacts into Feldspar Phenocrysts

    Get PDF
    Meteorite impact craters are the dominant surface feature on most terrestrial planetary bodies [1]. The extreme temperatures and pressures generated by hypervelocity impact events produce a variety of microscopic shock metamorphic effects in minerals, as well as non-exclusive shock-related features such as pervasive fracturing and brecciation. Studies of shock effects in feldspar group minerals have been limited due to the the comparatively rapid rate at which feldspars weather, and the complexity of their microtextures which renders them difficult to study using conventional optical techniques. However, feldspars are becoming increasingly investigated for use as shock barometers due to their importance in planetary studies and meteoritics, where rocks often contain little or no quartz [e.g., 2]. This provides the motivation to examine more closely the effects of high-velocity impact of a projectile, in the method of [3], into a feldspathic target, in order to the resultant microstructural variation.</p

    The cytoplasmic filaments of the nuclear pore complex are dispensable for selective nuclear protein import

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    The nuclear pore complex (NPC) mediates bidirectional macromolecular traffic between the nucleus and cytoplasm in eukaryotic cells. Eight filaments project from the NPC into the cytoplasm and are proposed to function in nuclear import. We investigated the localization and function of two nucleoporins on the cytoplasmic face of the NPC, CAN/Nup214 and RanBP2/Nup358. Consistent with previous data, RanBP2 was localized at the cytoplasmic filaments. In contrast, CAN was localized near the cytoplasmic coaxial ring. Unexpectedly, extensive blocking of RanBP2 with gold-conjugated antibodies failed to inhibit nuclear import. Therefore, RanBP2-deficient NPCs were generated by in vitro nuclear assembly in RanBP2-depleted Xenopus egg extracts. NPCs were formed that lacked cytoplasmic filaments, but that retained CAN. These nuclei efficiently imported nuclear localization sequence (NLS) or M9 substrates. NPCs lacking CAN retained RanBP2 and cytoplasmic filaments, and showed a minor NLS import defect. NPCs deficient in both CAN and RanBP2 displayed no cytoplasmic filaments and had a strikingly immature cytoplasmic appearance. However, they showed only a slight reduction in NLS-mediated import, no change in M9-mediated import, and were normal in growth and DNA replication. We conclude that RanBP2 is the major nucleoporin component of the cytoplasmic filaments of the NPC, and that these filaments do not have an essential role in importin /ß– or transportin-dependent import

    An interpretation of fluctuations in enzyme catalysis rate, spectral diffusion, and radiative component of lifetimes in terms of electric field fluctuations

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    Time-dependent fluctuations in the catalysis rate ({delta}k(t)) observed in single-enzyme experiments were found in a particular study to have an autocorrelation function decaying on the same time scale as that of spectral diffusion {delta}{omega}0(t). To interpret this similarity, the present analysis focuses on a factor in enzyme catalysis, the local electrostatic interaction energy (E) at the active site and its effect on the activation free energy barrier. We consider the slow fluctuations of the electrostatic interaction energy ({delta}E(t)) as a contributor to {delta}k(t) and relate the latter to {delta}{omega}0(t). The resulting relation between {delta}k(t) and {delta}{omega}0(t) is a dynamic analog of the solvatochromism used in interpreting solvent effects on organic reaction rates. The effect of the postulated {delta}E(t) on fluctuations in the radiative component ({delta}{gamma}Formula(t)) of the fluorescence decay of chromophores in proteins also is examined, and a relation between {delta}{gamma}Formula(t) and {delta}{omega}0(t) is obtained. Experimental tests will determine whether the correlation functions for {delta}k(t), {delta}{omega}0(t), and {delta}{gamma}Formula are indeed similar for any enzyme. Measurements of dielectric dispersion, {varepsilon}({omega}), for the enzyme discussed elsewhere will provide further insight into the correlation function for {delta}E(t). They also will determine whether fluctuations in the nonradiative component {gamma}Formula of the lifetime decay has a different origin, fluctuations in distance for example

    Maternal mental health research in Malawi: Community and healthcare provider perspectives on acceptability and ethicality

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    Maternal mental health (MMH) is recognised as globally significant. The prevalence of depression and factors associated with its onset among perinatal women in Malawi has been previously reported, and the need for further research in this domain is underscored. Yet, there is little published scholarship regarding the acceptability and ethicality of MMH research to women and community representatives. The study reported here sought to address this in Malawi by engaging with communities and healthcare providers in the districts where MMH research was being planned. Qualitative data was collected in Lilongwe and Karonga districts through 20 focus group discussions and 40 in-depth interviews with community representatives and healthcare providers from January through April 2021. All focus groups and interviews were audio recorded, transcribed verbatim (in local languages Chichewa and Tumbuka), translated into English, and examined through thematic content analysis. Participants' accounts suggest that biopsychosocial MMH research could be broadly acceptable within the communities sampled, with acceptability framed in part through prior encounters with biomedical and public health research and care in these regions, alongside broader understandings of the import of MMH. Willingness and consent to participate do not depend on specifically biomedical understandings of MMH, but rather on familiarity with individuals regarded as living with mental ill-health. However, the data further suggest some ‘therapeutic misconceptions’ about MMH research, with implications for how investigations in this area are presented by researchers when recruiting and working with participants. Further studies are needed to explore whether accounts of the acceptability and ethicality of MMH research shift and change during and following research encounters. Such studies will enhance the production of granular recommendations for further augmenting the ethicality of biomedical and public health research and researchers' responsibilities to participants and communities
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