23 research outputs found

    Fault-controlled hydration of the upper mantle during continental rifting

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    Water and carbon are transferred from the ocean to the mantle in a process that alters mantle peridotite to create serpentinite and supports diverse ecosystems1. Serpentinized mantle rocks are found beneath the sea floor at slow- to ultraslow-spreading mid-ocean ridges1 and are thought to be present at about half the world’s rifted margins2, 3. Serpentinite is also inferred to exist in the downgoing plate at subduction zones4, where it may trigger arc magmatism or hydrate the deep Earth. Water is thought to reach the mantle via active faults3, 4. Here we show that serpentinization at the rifted continental margin offshore from western Spain was probably initiated when the whole crust cooled to become brittle and deformation was focused along large normal faults. We use seismic tomography to image the three-dimensional distribution of serpentinization in the mantle and find that the local volume of serpentinite beneath thinned, brittle crust is related to the amount of displacement along each fault. This implies that sea water reaches the mantle only when the faults are active. We estimate the fluid flux along the faults and find it is comparable to that inferred for mid-ocean ridge hydrothermal systems. We conclude that brittle processes in the crust may ultimately control the global flux of sea water into the Earth

    Communication : where evolutionary linguistics went wrong

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    In this article we offer a detailed assessment of current approaches to the origins of language, with a special focus on their historical and theoretical underpinnings. It is a widely accepted view within evolutionary linguistics that an account of the emergence of human language necessarily involves paying special attention to its communicative function and its relation to other animal communication systems. Ever since Darwin, some variant of this view has constituted the mainstream version in evolutionary linguistics; however, it is our contention in this article that this approach is seriously flawed, and that "animal communication" does not constitute a natural kind on which a sound theoretical model can be built. As a consequence, we argue that this communicative perspective is better abandoned in favor of a structural/formal approach based on the notion of homology, and that some interesting and unexpected similarities may be found by applying this venerable comparative method founded in the 19th century by Richard Owen

    Effects of a mutual recovery intervention on mental health in depressed elderly community-dwelling adults: a pilot study

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    BackgroundThe prevalence of depression in the elderly is growing worldwide, and the population aging in China makes depression a major health problem for the elderly adults and a tremendous burden to the society. Effective interventions should be determined to provide an approach solving the problem and improving the situation. This study examined the effectiveness of a mutual recovery program intervention on depressive symptom, sleep quality, and well-being in community-dwelling elderly adults with depressive symptom in Shanghai.MethodsRecruitment was performed between July 2012 and August 2012. Using a cluster randomized wait-list controlled design, we randomized 6 communities (n = 237) into either the intervention group (3 communities, n = 105) or to a wait-list control group (3 communities, n = 132). All participants met the inclusion criteria for depression, which were defined by The Geriatric Depression Scale (GDS-15). From March to May of 2013, participants in the intervention group underwent a 2-month mutual recovery program intervention. The intervention included seven 90-min, weekly sessions that were based on a standardized self-designed schedule. Depression was used as primary outcome at three measurement moments: baseline (T1), before intervention at 24 weeks (T2), and immediately after intervention at 32 weeks (T3). Well-being and sleep quality were used as the secondary outcomes, and were evaluated based on the WHO-5 Well-being Index (WHO-5) and the Self-administered Sleep Questionnaire (SSQ). Finally, a total of 225 participants who completed all the sessions and the three measurements entered the final analysis. Mixed-model repeated measures ANOVAs were performed to estimate the intervention effects.ResultsThere was no significant difference in gender, marriage, age structure, post-work type, and education background between the intervention and control group at baseline. Multivariate ANOVAs showed that there was no significant difference within the groups in terms of sleep, well-being, and depression at baseline and before the intervention. Mixed-model repeated measures ANOVAs detected a group × time interaction on depression, sleep, and well-being and showed a favorable intervention effect within groups immediately after the intervention.ConclusionsThe mutual recovery program could be a creative and effective approach to improve mental health in older community-dwelling adults with depressive symptom

    Epistemic geographies of climate change: science, space and politics

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    Anthropogenic climate change has been presented as the archetypal global problem, identified by the slow work of assembling a global knowledge infrastructure, and demanding a concertedly global political response. But this ‘global’ knowledge has distinctive geographies, shaped by histories of exploration and colonialism, by diverse epistemic and material cultures of knowledge-making, and by the often messy processes of linking scientific knowledge to decision-making within different polities. We suggest that understanding of the knowledge politics of climate change may benefit from engagement with literature on the geographies of science. We review work from across the social sciences which resonates with geographers’ interests in the spatialities of scientific knowledge, to build a picture of what we call the epistemic geographies of climate change. Moving from the field site and the computer model to the conference room and international political negotiations, we examine the spatialities of the interactional co-production of knowledge and social order. In so doing, we aim to proffer a new approach to the intersections of space, knowledge and power which can enrich geography’s engagements with the politics of a changing climate

    Type/Typology

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    The concept of TYPE and the reference to a modality of thought characterized by a typological STYLE undoubtedly constitute characteristic elements of the morphological discourse, whether considered in its Goethean meaning, analysed starting from the many philosophical, naturalistic, poetological sources that come together in Goethe’s thought, or still because of the modern and contemporary developments that arose from the Goethean perspective in philosophy and in the natural sciences

    The interstellar and circumnuclear medium of active nuclei traced by H i 21 cm absorption

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