63 research outputs found

    TREX-DM: a low background Micromegas-based TPC for low mass WIMP detection

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    Dark Matter experiments are recently focusing their detection techniques in low-mass WIMPs, which requires the use of light elements and low energy threshold. In this context, we present the TREX-DM experiment, a low background Micromegas-based TPC for low-mass WIMP detection. Its main goal is the operation of an active detection mass \sim0.300 kg, with an energy threshold below 0.4 keVee and fully built with previously selected radiopure materials. This article describes the actual setup, the first results of the comissioning in Ar+2\%iC4_4H10_{10} at 1.2 bar and the future updates for a possible physics run at the Canfranc Underground Laboratory in 2016. A first background model is also presented, based on Geant4 simulations and a muon/electron discrimination method. In a conservative scenario, TREX-DM could be sensitive to DAMA/LIBRA and other hints of positive WIMPs signals, with some space for improvement with a neutron/electron discrimination method or the use of other light gases.Comment: Proceedings of the 7th Symposium on Large TPCs for Low-Energy Rare Event Detectio

    How stable are visions for protected area management? Stakeholder perspectives before and during a pandemic

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    Envisioning processes enable protected area managers to chart a course for future management to reach desired goals, but unexpected changes that could affect future visions are not usually considered. The global COVID-19 pandemic provided an opportunity to explore changes in stakeholder visions, the values that underpin the visions, and their perceptions of landscape changes and the underlying drivers (e.g. climate change, mass tourism and demographic trends).Through a mixed-methods approach in this post-evaluation study, we gathered comparative data on these issues from stakeholders in the Sierra de Guadarrama National Park, Spain, between July 2019 (pre-pandemic) and October 2020 (mid-pandemic).Our qualitative analysis demonstrates that pre-pandemic, differences in visions for protected area management were largely spurred by different perceptions of drivers of change, rather than differences in values or perceived landscape changes, which were similar across different vision themes.One year later, in the midst of the COVID-19 pandemic, the majority of stakeholders reported that their values, visions and perceptions of drivers did not change despite this large-scale disturbance. Of the 20%-30% of stakeholders that did report changes, visions generally shifted towards greater prioritization of biodiversity and nature conservation as a result of heightened perceptions of the impacts of drivers of change associated with an increase in the numbers of park visitors. These drivers included mass tourism, mountain recreation, lack of environmental awareness, and change in values and traditions.Our findings reinforce the importance of adaptive and inclusive management of protected areas, including enhancing transparency and communications regarding factors driving change in the landscape, and integration of local and traditional knowledge and stakeholder perceptions of changes and drivers. Furthermore, management plans integrating stakeholder values have the potential to stay relevant even in the face of wildcard events such as a pandemic.To enhance the relevancy of visions and scenarios in conservation and land-use planning, scenario planning methodologies should more strongly consider different potential disturbances and how drivers of change in the near and far future can be affected by wildcard events such as a pandemic. A free Plain Language Summary can be found within the Supporting Information of this article

    Impacto psicosocial en adultos con dermatitis atópica: estudio cualitativo

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    Antecedentes y objetivo La dermatitis atópica afecta a la calidad de vida del paciente de muchas maneras. Por tanto, es importante analizar los efectos que la enfermedad produce en la vida del paciente al objeto de definir mejor las necesidades de atención de los pacientes adultos con dermatitis atópica. Pacientes y métodos Se realizaron entrevistas a 14 pacientes adultos con dermatitis atópica. Las entrevistas cualitativas fueron semiestructuradas apoyadas en un guion simple, lo que permitió una entrevista completa y flexible para un mayor nivel de profundidad y riqueza de datos. Resultados Se identificaron 6 esferas afectadas de la vida del paciente con dermatitis atópica: económica, laboral, personal, psicosocial, clínica y relacional. Se destaca que la dermatitis atópica tiene un gran impacto psicosocial en el paciente adulto, ya que altera las relaciones interpersonales, genera rechazo, estigmatización y aislamiento social, limita al paciente en diversas áreas y actividades de su vida cotidiana o altera el sueño, entre otros. Preocupan mucho el aspecto visible, el ciclo picor-rascamiento, la falta de concienciación y desconocimiento de la enfermedad, la ausencia de una solución definitiva entre los tratamientos y los efectos secundarios de algunos de ellos. Conclusiones La calidad de vida de los pacientes con dermatitis atópica se ve afectada negativamente y se hace necesaria una intervención profesional desde un abordaje multidisciplinar holístico que intente mitigar el impacto negativo de la enfermedad. Background and objective: Atopic dermatitis affects a patient''s quality of life in many ways. Analysis of the effects of this disease on the lives of adult patients is therefore important for the purpose of better defining their care needs. Patients and methods: We interviewed 14 adult patients with atopic dermatitis in this qualitative study. The interviews were semistructured according to a simple outline to allow for completeness and flexibility and afford greater depth and richness of information. Results: Atopic dermatitis affected the patients’ lives in 6 spheres of activity: economic, occupational, personal, psychosocial, clinical, and relational. A clear finding was that the disease has a considerable psychosocial effect on adult patients, altering their interpersonal relationships and leading to rejection, stigmatization, and social isolation. It limits the patient in various spheres of life and in activities of daily living, causing sleep alterations among other effects. The patients were very concerned about appearance, the itch–scratch cycle, poor understanding and lack of awareness of their disease, the absence of a definitive treatment, and the adverse effects of some treatments. Conclusions: The quality of life of adults with atopic dermatitis is negatively affected. This disease requires a professional, holistic, multidisciplinary management approach that attempts to mitigate the adverse effects

    How stable are visions for protected area management? Stakeholder perspectives before and during a pandemic

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    Envisioning processes enable protected area managers to chart a course for future management to reach desired goals, but unexpected changes that could affect future visions are not usually considered. The global COVID-19 pandemic provided an opportunity to explore changes in stakeholder visions, the values that underpin the visions, and their perceptions of landscape changes and the underlying drivers (e.g. climate change, mass tourism and demographic trends). Through a mixed-methods approach in this post-evaluation study, we gathered comparative data on these issues from stakeholders in the Sierra de Guadarrama National Park, Spain, between July 2019 (pre-pandemic) and October 2020 (mid-pandemic). Our qualitative analysis demonstrates that pre-pandemic, differences in visions for protected area management were largely spurred by different perceptions of drivers of change, rather than differences in values or perceived landscape changes, which were similar across different vision themes. One year later, in the midst of the COVID-19 pandemic, the majority of stakeholders reported that their values, visions and perceptions of drivers did not change despite this large-scale disturbance. Of the 20%-30% of stakeholders that did report changes, visions generally shifted towards greater prioritization of biodiversity and nature conservation as a result of heightened perceptions of the impacts of drivers of change associated with an increase in the numbers of park visitors. These drivers included mass tourism, mountain recreation, lack of environmental awareness, and change in values and traditions. Our findings reinforce the importance of adaptive and inclusive management of protected areas, including enhancing transparency and communications regarding factors driving change in the landscape, and integration of local and traditional knowledge and stakeholder perceptions of changes and drivers. Furthermore, management plans integrating stakeholder values have the potential to stay relevant even in the face of wildcard events such as a pandemic. To enhance the relevancy of visions and scenarios in conservation and land-use planning, scenario planning methodologies should more strongly consider different potential disturbances and how drivers of change in the near and far future can be affected by wildcard events such as a pandemic. A free Plain Language Summary can be found within the Supporting Information of this article.Peer reviewe

    Inclusive conservation and the Post-2020 Global Biodiversity Framework : Tensions and prospects

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    Publisher Copyright: © 2022 The Author(s)The draft Post-2020 Global Biodiversity Framework commits to achievement of equity and justice outcomes and represents a “relational turn” in how we understand inclusive conservation. Although “inclusivity” is drawn on as a means to engage diverse stakeholders, widening the framing of inclusivity can create new tensions with regard to how to manage protected areas. We first offer a set of tensions that emerge in the light of the relational turn in biodiversity conservation. Drawing on global case examples applying multiple methods of inclusive conservation, we then demonstrate that, by actively engaging in the interdependent phases of recognizing hybridity, enabling conditions for reflexivity and partnership building, tensions can not only be acknowledged but softened and, in some cases, reframed when managing for biodiversity, equity, and justice goals. The results can improve stakeholder engagement in protected area management, ultimately supporting better implementation of global biodiversity targets.Peer reviewe

    The NEXT White (NEW) detector

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    Conceived to host 5 kg of xenon at a pressure of 15 bar in the fiducial volume, the NEXT-White apparatus is currently the largest high pressure xenon gas TPC using electroluminescent amplification in the world. It is also a 1:2 scale model of the NEXT-100 detector for Xe-136 beta beta 0 nu decay searches, scheduled to start operations in 2019. Both detectors measure the energy of the event using a plane of photomultipliers located behind a transparent cathode. They can also reconstruct the trajectories of charged tracks in the dense gas of the TPC with the help of a plane of silicon photomultipliers located behind the anode. A sophisticated gas system, common to both detectors, allows the high gas purity needed to guarantee a long electron lifetime. NEXT-White has been operating since October 2016 at the Laboratorio Subterraneo de Canfranc (LSC), in Spain. This paper describes the detector and associated infrastructures, as well as the main aspects of its initial operation

    Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements

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    We have investigated the possibility of calibrating the PMTs of scintillation detectors, using the primary scintillation produced by X-rays to induce single photoelectron response of the PMT. The high-energy tail of this response, can be approximated to an exponential function, under some conditions. In these cases, it is possible to determine the average gain for each PMT biasing voltage from the inverse of the exponent of the exponential fit to the tail, which can be done even if the background and/or noise cover-up most of the distribution. We have compared our results with those obtained by the commonly used single electron response (SER) method, which uses a LED to induce a single photoelectron response of the PMT and determines the peak position of such response, relative to the pedestal peak (the electronic noise peak, which corresponds to 0 photoelectrons). The results of the exponential fit method agree with those obtained by the SER method when the average number of photoelectrons reaching the first dynode per light/scintillation pulse is around 1.0. The SER method has higher precision, while the exponential fit method has the advantage of being useful in situations where the PMT is already in situ, being difficult or even impossible to apply the SER method, e.g. in sealed scintillator/PMT devices

    Accurate gamma and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atm

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    We report the performance of a 10 atm Xenon/trimethylamine time projection chamber (TPC) for the detection of X-rays (30 keV) and gamma-rays (0.511-1.275 MeV) in conjunction with the accurate tracking of the associated electrons. When operated at such a high pressure and in similar to 1%-admixtures, trimethylamine (TMA) endows Xenon with an extremely low electron diffusion (1.3 +/- 0.13 mm-sigma (longitudinal), 0.95 +/- 0.20 mm-sigma (transverse) along 1 m drift) besides forming a convenient Penning-Fluorescent' mixture. The TPC, that houses 1.1 kg of gas in its fiducial volume, operated continuously for 100 live-days in charge amplification mode. The readout was performed through the recently introduced microbulk Micromegas technology and the AFTER chip, providing a 3D voxelization of 8 mm x 8 mm x 1.2 mm for approximately 10 cm/MeV-long electron tracks. Resolution in energy (epsilon) at full width half maximum (R) inside the fiducial volume ranged from R = 14.6% (30 keV) to R = 4.6% (1.275 MeV). This work was developed as part of the R&D program of the NEXT collaboration for future detector upgrades in the search of the neutrino-less double beta decay (beta beta 0 nu) in Xe-136, specifically those based on novel gas mixtures. Therefore we ultimately focus on the calorimetric and topological properties of the reconstructed MeV-electron tracks. In particular, the obtained energy resolution has been decomposed in its various contributions and improvements towards achieving the R =1.4%root MeV/epsilon levels obtained in small sensors are discussedThe NEXT collaboration acknowledges funding support from the following agencies and institutions: European Research Council under Advanced Grant 339787-NEXT and Starting Grant 240054-TREX, Spanish Ministerio de Economia y Competitividad under grants Consolider-Ingenio 2010 CSD2008-0037 (CUP) and CSD2007-00042 (CPAN), contracts FPA2008-03456 and FPA2009-13697; Portuguese Fundacao para a Ciencia e a Tecnologia; European FEDER under grant PPTDC/FIS/103860/2008; US Department Of Energy under contract DE-AC02-05CH11231.Gonzalez Diaz, D.; Álvarez Puerta, V.; Borges, FIG.; Camargo, M.; Carcel, S.; Cebrian, S.; Cervera, A.... (2015). Accurate gamma and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atm. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 804:8-24. https://doi.org/10.1016/j.nima.2015.08.033S82480
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