100 research outputs found
Relativistic transition wavelenghts and probabilities for spectral lines of Ne II
Transition wavelengths and probabilities for several 2p4 3p - 2p4 3s and 2p4
3d - 2p4 3p lines in fuorine-like neon ion (NeII) have been calculated within
the multiconfiguration Dirac-Fock (MCDF) method with quantum electrodynamics
(QED) corrections. The results are compared with all existing experimental and
theoretical data
Socialâenvironmental drivers inform strategic management of coral reefs in the Anthropocene
Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblagesâthe foundation species of coral reef ecosystems. Here, we compiled coral abundance data from 2,584 Indo-Pacific reefs to evaluate the influence of 21 climate, social and environmental drivers on the ecology of reef coral assemblages. Higher abundances of framework-building corals were typically associated with: weaker thermal disturbances and longer intervals for potential recovery; slower human population growth; reduced access by human settlements and markets; and less nearby agriculture. We therefore propose a framework of three management strategies (protect, recover or transform) by considering: (1) if reefs were above or below a proposed threshold of >10% cover of the coral taxa important for structural complexity and carbonate production; and (2) reef exposure to severe thermal stress during the 2014â2017 global coral bleaching event. Our findings can guide urgent management efforts for coral reefs, by identifying key threats across multiple scales and strategic policy priorities that might sustain a network of functioning reefs in the Indo-Pacific to avoid ecosystem collapse
First measurement of Ωc0 production in pp collisions at s=13 TeV
The inclusive production of the charmâstrange baryon 0 c is measured for the first time via its hadronic â decay into âÏ+ at midrapidity (|y| <0.5) in protonâproton (pp) collisions at the centre-of-mass energy s =13 TeV with the ALICE detector at the LHC. The transverse momentum (pT) differential cross section multiplied by the branching ratio is presented in the interval 2 < pT < 12 GeV/c. The pT dependence of the 0 c-baryon production relative to the prompt D0-meson and to the prompt 0 c-baryon production is compared to various models that take different hadronisation mechanisms into consideration. In the measured pT interval, the ratio of the pT-integrated cross sections of 0 c and prompt + c baryons multiplied by the âÏ+ branching ratio is found to be larger by a factor of about 20 with a significance of about 4Ï when compared to e+eâ collisions
Taxonomic resolution needed to describe invertebrate assemblages and to detect harvesting effects on coral reef ecosystems
Due to the cost and time required for species identification, the taxonomic sufficiency approach has been developed in order to detect community response to a disturbance, using high taxonomic level without great loss of information. This concept has been widely applied to pollution monitoring studies but rarely to other forms of perturbations such as anthropogenic exploitation of marine resources. We applied this method both to soft-bottom (seagrasses) and hard-bottom (coralline) tropical invertebrate communities in New Caledonia, South Pacific. The objective was to test whether intermediate or high taxonomic levels (genus, family, class or phylum instead of species) are good descriptors of community patterns and changes in assemblages related to harvesting, by comparing harvested to non-harvested areas for the 2 habitats. We pooled species data into coarser taxonomic categories (from genus to phylum) and showed that matrices at different taxonomic resolutions were highly correlated, particularly for genus and family level for both habitats. Differences between harvested and non-harvested locations appeared to be clearly habitat-dependent; for soft habitats, genus and family resolution allowed the detection of changes between exploited and protected assemblages, while for hard habitats, the separation between harvested and non-harvested areas was less clear at high taxonomic level and required species-level identifications. These results suggest that the taxonomic sufficiency approach could be carefully applied to poorly known environments. Family level is a good descriptor of community composition for tropical reef invertebrates. Detecting changes due to anthropogenic exploitation requires different taxonomic resolutions depending on the considered habitat
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