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K. El Hanafi, B. Gomez-Gomez, Z. Pedrero, P. Bustamante, Y. Cherel, D. Amouroux, Y. Madrid. (2023). Simple and rapid formic acid sample treatment for the isolation of HgSe nanoparticles from animal tissues (Vol. 1250).
Abstract: The present work explores for the first time the potential of formic acid on the extraction of tiemannite (HgSe) nanoparticles from seabird tissues, in particular giant petrels. Mercury (Hg) is considered one of the top ten chemicals of major public health concern. However, the fate and metabolic pathways of Hg in living organisms remain unknown. Methylmercury (MeHg), largely produced by microbial activity in the aquatic ecosystems is biomagnified in the trophic web. HgSe is considered the end-product of MeHg demethylation in biota and an increasing number of studies focuses on the characterization of this solid compound to understand its biomineralization. In this study, a conventional enzymatic treatment is compared with a simpler and environmentally friendly extraction by using formic acid (5 mL of = 50 % formic acid) as exclusive reagent. The analyses by spICP-MS of the resulting extracts from a variety of seabird biological tissues (liver, kidneys, brain, muscle) reveal comparable results by both extraction approaches in terms of nanoparticles stability and extraction efficiency. Therefore, the results included in this work demonstrate the good performance of employing organic acid as simple, cost effective and green procedure to extract HgSe nanoparticles from animal tissues. Moreover, an alternative consisting of a classical enzymatic procedure but with ultrasonic assistance reducing the extraction time from 12 h to 2 min is also described for the first time. The sample processing methodologies developed, combined with spICP-MS, have emerged as powerful tools for the rapid screening and quantification of HgSe nanoparticles in animal tissues. Finally, this combination allowed us to identify the possible occurrence of Cd particles and As particles associated with HgSe NPs in seabirds.
Keywords: Mercury Sample treatment Seabirds Selenium spICP-MS Tiemannite
Programme: 109
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. (2019). Using blood and feathers to investigate large-scale Hg contamination in Arctic seabirds: A review (Vol. 177). Bachelor's thesis, , .
Abstract: Mercury (Hg), because of its deleterious effects on wildlife and its high concentrations in polar regions, has been widely studied in the Arctic. This provided important information regarding food web contamination, spatial and temporal trends of Hg in ecosystems or risk assessments for wildlife and Humans. Among the Arctic biota, seabirds have been among the most studied species due to their sensitivity to this toxicant, their role as bioindicators of the contamination status of their environment, and their consumption by Arctic communities. However, most studies that investigated Hg in Arctic seabirds focused on measurements in internal organs or in eggs, while few investigations have been performed on blood and feathers, despite the relevant and complementary information they provide. Here, we first provide a detailed overview of the specific information blood and feathers can bring when investigating Hg contamination of Arctic seabirds, including new knowledge on the poorly studied non-breeding period. Second, we perform a comprehensive review of the use of blood and feathers as non-lethal tissues to study Hg in Arctic seabirds. This review demonstrates important interspecific variations in Hg blood concentrations according to seabird trophic status, with seaducks generally presenting the lowest Hg concentrations while auks have the highest ones. However, all the observed Hg concentrations are below the admitted toxicity thresholds. Hg concentrations in feathers follow similar trends and gulls appear to be the most contaminated species, likely as a consequence of contrasting migratory and overwintering strategies. This review also confirms strong spatial variations with higher concentrations found in the Canadian Arctic and Pacific waters than in Greenland and the European Arctic. It also identifies some major understudied areas such as West Greenland, Aleutian Islands and Russia. Finally, we provide a thorough review of the current knowledge regarding molting patterns in Arctic seabirds, which is an essential information to interpret Hg concentrations measured in feathers. Overall, our results point out the importance of blood and feathers in seabird ecotoxicological assessments and highlight the need for large scale international collaborations and research programs.
Keywords: Mercury Molting pattern Seabirds Spatial ecotoxicology
Programme: 388
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Bart Van de Vijver, Richard M. Crawford. (2019). Melosira jeanbertrandiana, a new Melosira species (Bacillariophyceae) from the sub-Antarctic region (Vol. 167).
Abstract: During a survey of the soil diatom flora of the sub-Antarctic Ile de la Possession (Iles Crozet), located in the southern Indian Ocean, an unknown Melosira species was found that could not be identified using the currently available literature on the genus. The species is described as Melosira jeanbertrandiana sp. nov. based on detailed light and scanning electron microscopy observations. The new species is characterized by a relatively high mantle, the presence of several marginal rings of acute, never bifurcating spines and a series of eight rimoportulae near the central area with several others scattered over the rest of the valve face and mantle. The girdle comprising several large, ligulate open copulae and the position of the rimoportulae clearly place this new species within the genus Melosira C.Agardh. The species was observed in bare, moist soil in scratches in cliffs bordering the ocean where the influence of sea spray is obvious. The description of this new species further increases the number of species of the Melosirales compared to other centric freshwater diatoms which are infrequently found on the sub-Antarctic islands.
Keywords: Melosira melosiroid genera morphology new species Sub-Antarctica
Programme: 136
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Branger Karine, Drillet Yann, Houssais Marie-Nolle, Testor Pierre, Bourdall-Badie Romain, Alhammoud Bahjat, Bozec Alexandra, Mortier Laurent, Bouruet-Aubertot Pascale, Crpon Michel, . (2010). Impact of the spatial distribution of the atmospheric forcing on water mass formation in the Mediterranean Sea
. J. Geophys. Res., 115(C12), C12041–.
Keywords: Mediterranean Sea, deep water formation, numerical modeling, atmospheric forcing, 4504 Oceanography: Physical: Air/sea interactions, 4215 Oceanography: General: Climate and interannual variability, 4513 Oceanography: Physical: Decadal ocean variability, 4283 Oceanography: General: Water masses, 4520 Oceanography: Physical: Eddies and mesoscale processes,
Programme: 452
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. (2017). Implantation of subcutaneous heart rate data loggers in southern elephant seals (Mirounga leonina) (Vol. 40).
Keywords: Marine mammals Pinnipeds Surgery
Programme: 1201
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Durand G, Gagliardini O, de Fleurian B, Zwinger T, Le Meur E, . (2009). Marine ice sheet dynamics: Hysteresis and neutral equilibrium
. J. Geophys. Res., 114(F3), F03009–.
Keywords: marine ice sheet, grounding line, full Stokes modeling, 0774 Cryosphere: Dynamics, 0726 Cryosphere: Ice sheets, 0728 Cryosphere: Ice shelves, 0798 Cryosphere: Modeling,
Programme: 1053
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Chengbin Peng, Carlos M. Duarte, Daniel P. Costa, Christophe Guinet, Robert G. Harcourt, Mark A. Hindell, Clive R. McMahon, Monica Muelbert, Michele Thums, Ka-Chun Wong, Xiangliang Zhang. (2019). Deep Learning Resolves Representative Movement Patterns in a Marine Predator Species (Vol. 9).
Abstract: The analysis of animal movement from telemetry data provides insights into how and why animals move. While traditional approaches to such analysis mostly focus on predicting animal states during movement, we describe an approach that allows us to identify representative movement patterns of different animal groups. To do this, we propose a carefully designed recurrent neural network and combine it with telemetry data for automatic feature extraction and identification of non-predefined representative patterns. In the experiment, we consider a particular marine predator species, the southern elephant seal, as an example. With our approach, we identify that the male seals in our data set share similar movement patterns when they are close to land. We identify this pattern recurring in a number of distant locations, consistent with alternative approaches from previous research.
Keywords: marine animal movement analysis recurrent neural networks representative patterns
Programme: 1201
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Claeys Magda, Wang Wan, Vermeylen Reinhilde, Kourtchev Ivan, Chi Xuguang, Farhat Yasmeen, Surratt Jason D, Gmez-Gonzlez Yadian, Sciare Jean, Maenhaut Willy,. (2010). Chemical characterisation of marine aerosol at Amsterdam Island during the austral summer of 2006-2007. Journal of Aerosol Science, 41(1), 13–22.
Keywords: Marine aerosols, Water-soluble organic carbon, Secondary organic aerosol, Organosulphates, Isoprene,
Programme: 414;415
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Ritsema Jeroen, Xu Wenbo, Stixrude Lars, Lithgow-Bertelloni Carolina, . (2009). Estimates of the transition zone temperature in a mechanically mixed upper mantle
. Earth and Planetary Science Letters, 277(12), 244–252.
Keywords: mantle, mechanical mixing, mineral physics, travel times, temperature,
Programme: 133
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Bai L, Ritsema J, . (2013). The effect of large-scale shear-velocity heterogeneity on SS precursor amplitudes
. Geophysical Research Letters, 40(23), 6054–6058.
Keywords: mantle transition zone, SS precursors, velocity heterogeneity, amplitude, 1734 Seismology, 7290 Computational seismology, 8124 Earth's interior: composition and state,
Programme: 133
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