New Experiments With Spheres-Gas (NEWS-G) is a direct dark matter detection experiment using SphericalProportional Counters (SPCs) with light noble gases to search for low-mass Weakly Interacting Massive Particles (WIMPs). We report the results from the first physics run taken at the Laboratoire Souterrain de Modane (LSM) with SEDINE, a 60 cm diameter prototype SPC operated with a mixture of Ne + CH 4 (0.7 %) at 3.1 bars for a total exposure of 9.7 kg · days. New constraints are set on the spin-independent WIMP-nucleon scattering cross-section in the sub-GeV/c 2 mass region. We exclude cross-sections above 4.4 × 10 −37 cm 2 at 90 % confidence level (C.L.) for a 0.5 GeV/c 2 WIMP. The competitive results obtained with SEDINE are promising for the next phase of the NEWS-G experiment: a 140 cm diameter SPC to be installed at SNOLAB by summer 2018.
This document is the work of a team assembled by the International Coral Reef Society (ICRS). The mission of ICRS is to promote the acquisition and dissemination of scientific knowledge to secure the future of coral reefs, including via relevant policy frameworks and decision-making processes. This document seeks to highlight the urgency of taking action to conserve and restore reefs through protection and management measures, to provide a summary of the most relevant and recent natural and social science that provides guidance on these tasks, and to highlight implications of these findings for the numerous discussions and negotiations taking place at the global level.
Spherical Proportional Counters (SPCs) are a novel gaseous detector technology employed by the NEWS-G low-mass dark matter search experiment for their high sensitivity to single electrons from ionization. In this paper, we report on the first characterization of the single electron response of SPCs with unprecedented precision, using a UV-laser calibration system. The experimental approach and analysis methodology are presented along with various direct applications for the upcoming next phase of the experiment at SNOLAB. These include the continuous monitoring of the detector response and electron drift properties during dark matter search runs, as well as the experimental measurement of the trigger threshold efficiency. We measure a mean ionization energy of W = 27.6 ± 0.2 eV in Ne + CH4 (2%) for 2.8 keV X-rays, and demonstrate the feasibility of performing similar precision measurements at sub-keV energies for future gas mixtures to be used for dark matter searches at SNOLAB.
ABSTRACT1. Creating representative networks of marine protected areas (MPAs) as part of an ecosystem-based management approach is generally advocated to protect the full spectrum of marine ecosystems and vulnerable species. Core objectives for designing MPA networks incorporate issues of scale, size and spacing. Ascertaining when such objectives have been met, and thus when a network can be judged to be ecologically coherent, presents an ongoing challenge. This paper presents a broad-scale approach to assess the degree of ecological coherence within one such network.2. In 2013 an independent ecological coherence assessment was requested by OSPAR, the Regional Seas Convention for the North-east Atlantic, of the ecological coherence of its regional MPA network. As is often the case in the marine environment, the data were not sufficiently comprehensive or spatially inclusive to allow for a thorough assessment for the entire region. Consequently two levels of testing were applied: (1) basic tests applied to the whole OSPAR maritime area; and (2) a more sophisticated second level of tests directed at specific OSPAR regions and subregions for which more complete datasets were available. The former considered major gaps based on basic distribution thresholds and representativity (both biogeographic and bathymetric). The latter focused on broad-scale habitat presence to determine replication, adequacy and connectivity.3. On the basis of these tests it was concluded that while the OSPAR MPA network as a whole is not ecologically coherent, nonetheless significant progress towards global targets, such as protection of 10% of marine and coastal environments under the Convention on Biological Diversity (CBD) has been made. Gaps in the distribution of MPAs were identified, particularly under-representation of certain biogeographic provinces and bathymetric zones of depths greater than 75 m including bathyal (200-3000 m) and abyssal (3000-6000 m) depths.4. To address such gaps, a cooperative region by region approach will be required by the OSPAR Parties to identify where positioning new MPAs can enhance ecological coherence. 5. A limitation of the 2013 assessment was that it did not consider which MPAs are designated and managed for the protection of specific features; rather, it assumed that all features that fall within an MPA are protected. With a redevelopment of the OSPAR MPA database underway it is hoped that reporting of such details by Parties will improve, allowing for more specificity in future analyses. However, as the first such assessment of its kind our two-level approach serves as a case study of a pragmatic example of how assessments of ecologically coherent networks might be undertaken using GIS to contribute to systematic conservation planning.
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