1,529 research outputs found

    Lava channel formation during the 2001 eruption on Mount Etna: evidence for mechanical erosion

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    We report the direct observation of a peculiar lava channel that was formed near the base of a parasitic cone during the 2001 eruption on Mount Etna. Erosive processes by flowing lava are commonly attributed to thermal erosion. However, field evidence strongly suggests that models of thermal erosion cannot explain the formation of this channel. Here, we put forward the idea that the essential erosion mechanism was abrasive wear. By applying a simple model from tribology we demonstrate that the available data agree favorably with our hypothesis. Consequently, we propose that erosional processes resembling the wear phenomena in glacial erosion are possible in a volcanic environment.Comment: accepted for publication in Physical Review Letter

    The MEV project: design and testing of a new high-resolution telescope for Muography of Etna Volcano

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    The MEV project aims at developing a muon telescope expressly designed for the muography of Etna Volcano. In particular, one of the active craters in the summit area of the volcano would be a suitable target for this experiment. A muon tracking telescope with high imaging resolution was built and tested during 2017. The telescope is a tracker based on extruded scintillating bars with WLS fibres and featuring an innovative read-out architecture. It is composed of three XY planes with a sensitive area of \SI{1}{m^2}; the angular resolution does not exceeds \SI{0.4}{\milli\steradian} and the total angular aperture is about ±\pm\SI{45}{\degree}. A special effort concerned the design of mechanics and electronics in order to meet the requirements of a detector capable to work in a hostile environment such as the top of a tall volcano, at a far distance from any facility. The test phase started in January 2017 and ended successfully at the end of July 2017. An extinct volcanic crater (the Monti Rossi, in the village of Nicolosi, about 15km from Catania) is the target of the measurement. The detector acquired data for about 120 days and the preliminary results are reported in this work

    The Life Esidimeni tragedy: A human-rights perspective

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    The International Covenant on Economic, Social and Cultural Rights (ICESCR) affirms that all human beings are entitled to core rights essential to human fulfilment. Although all human rights are important, the ICESCR’s guarantee of the right of everyone to the enjoyment of the highest attainable standard of physical and mental health may be the most significant. Having good health is necessary for human wellbeing. Paramount to this is the freedom of individuals to exercise their human rights. As seen with the Life Esidimeni tragedy, people with mental illnesses often find it more difficult than others to achieve the fulfilment of their rights. This article discusses human-rights legal instruments, and focuses on the rights to health, life and dignity in the context of the tragedy. It also examines how the realisation of human rights can have meaningful results for mentally ill people

    Typical carcinoid tumor of the larynx in a woman: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Neuroendocrine tumors are the second most common neoplasms of the larynx. Histopathologically, neuroendocrine tumors can be classified into four types: typical carcinoid tumors, atypical carcinoid tumors, small cell neuroendocrine tumors and paragangliomas. Typical carcinoid tumor of the larynx is a particularly rare occurrence. We present a case of this rare disease, and review and discuss its diagnosis and treatment.</p> <p>Case presentation</p> <p>A 55-year-old Turkish woman presented with a two-year history of persistent hoarseness. Endoscopic laryngeal examination and computed tomography revealed a supraglottic mass. Direct laryngoscopy was performed and a biopsy taken. Results of the histopathologic examination and immunohistochemical analysis were consistent with typical carcinoid tumor of the larynx. A supraglottic laryngectomy was performed. There was no recurrence during a follow-up period of three years.</p> <p>Conclusion</p> <p>Carcinoid tumors require an accurate diagnosis because of their varied clinical behavior and prognosis. A correct pathologic diagnosis is essential, differentiating the tumors from other neuroendocrine neoplasms and medullary cancer of the thyroid gland. Immunohistochemical analysis is supplementary to a standard histopathologic evaluation. Currently, conservative surgical resection without elective neck dissection is the recommended treatment for typical carcinoid tumor of the larynx. Additional cases and case series with long-term follow-up will be useful for understanding the nature of this tumor and should clarify the prognosis.</p

    Responses of four winegrape varieties to managed water stress and partial defoliation in an arid environment

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    In viticulture, the imposition of managed water deficits is a strategy which has been used to increase both water use efficiency and winemaking quality in arid climates. Partial defoliation early in the season is another innovative practice that may also be used as an aid in regulating yield components and improving fruit quality. The aim of this work was to evaluate the effects of managed water stress and early season partial defoliation on crop yield and quality in two autochthonous (‘Frappato’ and ‘Nero d’Avola’) and two international varieties (‘Syrah’ and ‘Cabernet Sauvignon’) growing in an arid environment. The four treatments were: (i) no leaf removal, un-irrigated, (ii) no leaf removal, irrigated at 30 % of estimated crop evapotranspiration (ETc), (iii) partial leaf removal, un-irrigated, and (iv) partial leaf removal, irrigated at 30 % of estimated ETc. The results confirm the effectiveness of partial defoliation in yield management which leads to smaller clusters. Managed water stress was also an effective strategy for reducing berry size, improving must quality and generally enhancing anthocyanin accumulation.
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