204 research outputs found

    Interaction of gases with lunar materials

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    The surface properties of lunar fines were investigated. Results indicate that, for the most part, these properties are independent of the chemical composition and location of the samples on the lunar surface. The leaching of channels and pores by adsorbed water vapor is a distinguishing feature of their surface chemistry. The elements of air, if adsorbed in conjunction with water vapor or liquid water, severely impedes the leaching process. In the absence of air, liquid water is more effective than water vapor in attacking the grains. The characteristics of Apollo 17 orange fines were evaluated and compared with those of other samples. The interconnecting channels produced by water vapor adsorption were found to be wider than usual for other types of fines. Damage tracks caused by heavy cosmic ray nuclei and an unusually high halogen content might provide for stronger etching conditions upon exposure to water vapor

    Interaction of gases with lunar materials

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    The surface chemistry of Apollo 17 lunar fines samples 74220 (the orange soil) and 74241 (the gray control soil) has been studied by measuring the adsorption of nitrogen, argon, and oxygen (all at 77 K) and also water vapor (at 20 or 22 C). In agreement with results for samples from other missions, both samples had low initial specific surface areas, consisted of nonporous particles, and were attacked by water vapor at high relative pressure to give an increased specific surface area and create a pore system which gave rise to a capillary condensation hysteresis loop in the adsorption isotherms. In contrast to previous samples, both of the Apollo 17 soils were partially hydrophobic in their initial interaction with water vapor (both samples were completely hydrophilic after the reaction with water). The results are consistent with formation at high temperatures without subsequent exposure to significant amounts of water

    Research on stimulated exoelectron emission from lunar materials Technical progress report

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    Preliminary results on thermally stimulated exoelectron emission from Apollo 12 lunar material

    Interaction of gases with lunar materials

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    Quantitative efforts to assess the surface properties of lunar fines, particularly water induced porosity are discussed. Data show that: (1) changes induced in lunar fines are not visible in high energy electron micrographs, (2) scanning micrographs show no change in particle size distribution as a result of reaction with water, (3) water induced changes are internal to the particles themselves, (4) normal laboratory atmosphere blocks alteration reaction with water, and (5) surface properties of mature lunar soils appear to be almost independent of chemical composition and mineralogy, but there are some variations in their reactivity toward water

    Genome editing in mitochondria corrects a pathogenic mtDNA mutation in vivo.

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    Mutations of the mitochondrial genome (mtDNA) underlie a substantial portion of mitochondrial disease burden. These disorders are currently incurable and effectively untreatable, with heterogeneous penetrance, presentation and prognosis. To address the lack of effective treatment for these disorders, we exploited a recently developed mouse model that recapitulates common molecular features of heteroplasmic mtDNA disease in cardiac tissue: the m.5024C>T tRNAAla mouse. Through application of a programmable nuclease therapy approach, using systemically administered, mitochondrially targeted zinc-finger nucleases (mtZFN) delivered by adeno-associated virus, we induced specific elimination of mutant mtDNA across the heart, coupled to a reversion of molecular and biochemical phenotypes. These findings constitute proof of principle that mtDNA heteroplasmy correction using programmable nucleases could provide a therapeutic route for heteroplasmic mitochondrial diseases of diverse genetic origin

    Tangible landscapes and abstract narratives

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    © 2020 Association for Computing Machinery. The Tangible Landscapes range of interactive audiovisual and sculptural pieces offer audiences opportunities to explore abstract landscapes, recreating an embodied experience of the materials, through tangible interaction with found objects. The objects can contain sensors (tilt, orientation, movement, proximity, pressure, etc) which allow the audience to manipulate the video material through the sensors influencing the algorithms in the system. New meanings and new narratives can emerge from the audience interactions, explorations and interpretations, combining the individual and social, as well as the intimate and the spatial. Interactive art in general, and these pieces in particular, encourage and support the audience to create their own unique experiences, allowing for an individual sense of agency. The resulting patterns and images that emerge from the interaction, though these deliberate opportunities, a participative process of co-creating. This paper presents a range of these Tangible Landscape pieces, their relationship with earlier pieces and research, and placed in a context of artistic expression engaging with nature such as Landscape Art

    Impact of financial inclusion in low- and middle-income countries: a systematic review of reviews

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    Financial inclusion programmes seek to increase access to financial services such as credit, savings, insurance and money transfers and so allow poor and low-income households in low- and middle-income countries to enhance their welfare, grasp opportunities, mitigate shocks, and ultimately escape poverty. This systematic review of reviews assesses the evidence on economic, social, behavioural and gender-related outcomes from financial inclusion. It collects and appraises all of the existing meta-studies - that is systematic reviews and meta-analyses - of the impact of financial inclusion. The authors first analyse the strength of the methods used in those meta-studies, then synthesise the findings from those that are of a sufficient quality, and finally, report the implications for policy, programming, practice and further research arising from the evidence. Eleven studies are included in the analysis
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