72 research outputs found
Sympathy for the Devil: A Conservation Strategy for Devil and Manta Rays
Background International trade for luxury products, medicines, and tonics poses a threat to both terrestrial and marine wildlife. The demand for and consumption of gill plates (known as Peng Yu Sai, “Fish Gill of Mobulid Ray”) from devil and manta rays (subfamily Mobulinae, collectively referred to as mobulids) poses a significant threat to these marine fishes because of their extremely low productivity. The demand for these gill plates has driven an international trade supplied by largely unmonitored and unregulated catches from target and incidental fisheries around the world. Scientific research, conservation campaigns, and legal protections for devil rays have lagged behind those for manta rays despite similar threats across all mobulids.
Methods To investigate the difference in attention given to devil rays and manta rays, we examined trends in the scientific literature and updated species distribution maps for all mobulids. Using available information on target and incidental fisheries, and gathering information on fishing and trade regulations (at international, national, and territorial levels), we examined how threats and protective measures overlap with species distribution. We then used a species conservation planning approach to develop the Global Devil and Manta Ray Conservation Strategy, specifying a vision, goals, objectives, and actions to advance the knowledge and protection of both devil and manta rays.
Results and Discussion Our literature review revealed that there had been nearly 2.5-times more “manta”-titled publications, than “mobula” or “devil ray”-titled publications over the past 4.5 years (January 2012–June 2016). The majority of these recent publications were reports on occurrence of mobulid species. These publications contributed to updated Area of Occupancy and Extent of Occurrence maps which showed expanded distributions for most mobulid species and overlap between the two genera. While several international protections have recently expanded to include all mobulids, there remains a greater number of national, state, and territory-level protections for manta rays compared to devil rays. We hypothesize that there are fewer scientific publications and regulatory protections for devil rays due primarily to perceptions of charisma that favour manta rays. We suggest that the well-established species conservation framework used here offers an objective solution to close this gap. To advance the goals of the conservation strategy we highlight opportunities for parity in protection and suggest solutions to help reduce target and bycatch fisheries
Guidance on Monitoring of Marine Litter in European Seas
This publication is a Reference Report by the Joint Research Centre of the European Commission.The MSFD Technical Subgroup on Marine Litter was tasked to deliver guidance so that European Member States could
initiate programmes for monitoring of Descriptor 10 of the MSFD. The present document provides the recommendations
and information needed to commence the monitoring required for marine litter, including methodological protocols and
categories of items to be used for the assessment of litter on the Beach, Water Column, Seafloor and Biota, including a
special section on Microparticles
Limits on the production of scalar leptoquarks from Z (0) decays at LEP
A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)
Invariant mass dependence of particle correlations in hadronic final states from the decay of the Z
Calorimetric and Positron Lifetime Measurements οf Hydrogenated Carbon Nanocones
Two carbon nano-structured samples containing 5 and 20% of carbon nanocones in their volume were investigated. Using the Sieverts apparatus the hydrogen was loaded into the samples. The measurements of heat capacity in the temperature range from 100 K to 320 K and the positron lifetime measurements at the room temperature were performed for hydrogenated and non-hydrogenated carbon nanocones. The desorption of hydrogen at the temperature of 230 K is deduced from the heat capacity measurements. The detection of the positronium, the bound state of positron and electron, in the measured samples reveals the presence of open volume defects of ca. 0.198 ± 0.002 nm
Calorimetric and Positron Lifetime Measurements οf Hydrogenated Carbon Nanocones
Two carbon nano-structured samples containing 5 and 20% of carbon nanocones in their volume were investigated. Using the Sieverts apparatus the hydrogen was loaded into the samples. The measurements of heat capacity in the temperature range from 100 K to 320 K and the positron lifetime measurements at the room temperature were performed for hydrogenated and non-hydrogenated carbon nanocones. The desorption of hydrogen at the temperature of 230 K is deduced from the heat capacity measurements. The detection of the positronium, the bound state of positron and electron, in the measured samples reveals the presence of open volume defects of ca. 0.198 ± 0.002 nm
A nuclear magnetic resonance study of SmMn2H2
A Sm-147 and Sm-149 nuclear magnetic resonance study of the hydride SmMn2H2 at 4.2 K is reported. Well resolved quadrupole septets are observed in the spectra of both isotopes. The value of the hyperfine field, 342.7 T, corresponds with the fully polarised magnetic state, J(7)=J=5/2, of samarium in the compound. The magnitude of the electric field gradient derived from the line separation in the spectra and the quadrupole oscillations of the spin echo decay curves reveals a considerable lattice contribution to the electric field gradient. The results are discussed in terms of the influence of hydrogen on the contribution of Sm to the magnetocrystalline anisotropy of the compound and a conclusion about the magnetic structure of the compound is given. (C) 2002 Elsevier Science B.V. All rights reserved.</p
Hydrogen induced structural and magnetic transformations in the hexagonal Laves phase ErMn 2
Abstract Powder samples of hexagonal Laves phase ErMn 2 H x hydrides, with 0 < x ≤ 4.3, are characterised by X-ray analysis and SQUID magnetometry for temperatures ranging between 2 and 375 K. Structural transformations as function of the hydrogen concentration and temperature were observed. In particular, a decomposition of spinodal type has been found. It has been shown that structural transformations are reflected in the magnetic behaviour and that an increase of the Mn-Mn distance above the critical distance causes appearance of Mn magnetic moments. The analysis of the magnetic data as function of the hydrogen content, temperature and magnetic field shows that the Mn magnetic moments are antiferromagnetically coupled. The behaviour of these hydrides is compared with the properties of cubic hydrides
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