Two symmetric ligands harbouring two TEMPO radicals and two functionalized acetamide arms (R = OMe (L1), CF3 (L2)) were prepared and chelated to lanthanide ions (EuIII, YbIII for both L1 and L2, DyIII for L1). Luminescence measurements on the europium complexes support the coordination of a single water molecule. The TEMPO arms are magnetically interacting in L1 (and its complexes) but not in L2. The TEMPO moieties can be reversibly oxidized into an oxoammonium (0.33-0.36 V vs. Fc+/Fc) or reduced into a hydroxylamine (ill-defined redox wave, reduction by ascorbate), which are both diamagnetic. The europium complexes [Eu(L1)]3+ and [Eu(L2)]3+ in their hydroxylamine form exhibit a temperature dependent CEST effect, which is maximal at 25 °C (30%) and 37 °C (12%), respectively. The CEST activity is dramatically reduced in the corresponding nitroxide forms due to the paramagnetism of the ligand. The europium complexes show no cytotoxicity against M21 cell lines over long incubation times (72 h) at high concentration (40 μM).

The White-breasted Thrasher (Ramphocinclus brachyurus) is the smallest passerine bird in the Mimids family.Ranked as "endangered" in the IUCN list, the demographic distribution of this species is spread unevenly across two islands in the Lesser Antilles.The Saint-Lucian subspecies, Ramphocinclus brachyurus sanctaeluciae, was estimated to number between 1200 and 1700 individuals, whereas the Martinique subspecies, Ramphocinclus brachyurus brachyurus, was estimated at between 200 and 400 individuals.As

Three lanthanide complexes (Ln=Gd, Eu) based on a DO3 A ([Ln(L1 )]) or DO2 A ([Ln(L2-3 )]+ ) platform appended by a redox active TEMPO-based arm were prepared. Complex [Ln(L2 )]+ shows an alkyne arm, offering the possibility of postfunctionalization by click reaction to yield [Ln(L3 )]+ . The complexes demonstrate a redox response whereby the hydroxylamine, nitroxide and oxoammonium forms of the arm can be obtained in turn. Luminescence measurements on the europium complexes support an octadentate (L1 , L3 ) or heptadentate (L2 ) chelation by the ligand, with one water molecule in the inner coordination sphere. The relaxivity was determined from 20 kHz to 30 MHz by fast-field cycling NMR. The three GdIII complexes under their hydroxylamine form [Gd(L1 )] and [Gd(L2-3 )]+ show r1 values of 7.0, 5.1 and 5.0 mM-1 s-1 (30 KHz), which increase to 8.8, 5.5 and 6.1 mM-1 s-1 in the nitroxide form. The radical complexes are not toxic against M21 cell lines, at least up to 40 μM. By using EPR spectroscopy we establish that they do not penetrate the cells with the exception of [Eu(L2 )]+ .

Le projet PROTÉGER vise à promouvoir les techniques de génie végétal pour préserver l’extrême biodiversité des milieux rivulaires de Guadeloupe, tout en protégeant la population et leurs biens, des risques encourus lors des crues de rivière et des évènements cycloniques. La première phase du projet a consisté à décrire les ripisylves de l’archipel, afin d’en connaitre les modèles naturels et de pouvoir s’en inspirer pour développer des solutions fondées sur la nature. Sur les 270 berges échantillonnées, 302 espèces dont 231 indigènes ont été rencontrées, soit 10 % de la flore locale, reflétant la nature très forestière de l’archipel et son exceptionnelle diversité. L’analyse de ces relevés a permis de définir 12 types de ripisylves, et de documenter 80 espèces potentiellement utilisables en génie végétal. L’étude présente 30 d'entre elles sous forme de fiches individuelles disponibles sur le site internet du projet avec leur description, leur phénologie, leur statut de protection, leur écologie, leur usage et leur condition d’utilisation. Au-delà de la typologie et des fiches spécifiques, ce travail a aussi montré l’état alarmant des ripisylves de Guadeloupe, notamment sur la partie aval des cours d‘eau, avec des habitats dégradés par la pollution et la présence d’espèces exotiques envahissantes.

Abstract Three lanthanide complexes (Ln=Gd, Eu) based on a DO3 A ([Ln(L1)]) or DO2 A ([Ln(L2–3)]+ ) platform appended by a redox active TEMPO‐based arm were prepared. Complex [Ln(L2)]+ shows an alkyne arm, offering the possibility of postfunctionalization by click reaction to yield [Ln(L3)]+ . The complexes demonstrate a redox response whereby the hydroxylamine, nitroxide and oxoammonium forms of the arm can be obtained in turn. Luminescence measurements on the europium complexes support an octadentate (L1 , L3 ) or heptadentate (L2 ) chelation by the ligand, with one water molecule in the inner coordination sphere. The relaxivity was determined from 20 kHz to 30 MHz by fast‐field cycling NMR. The three GdIII complexes under their hydroxylamine form [Gd(L1)] and [Gd(L2–3)]+ show r1 values of 7.0, 5.1 and 5.0 mM−1 s−1 (30 KHz), which increase to 8.8, 5.5 and 6.1 mM−1 s−1 in the nitroxide form. The radical complexes are not toxic against M21 cell lines, at least up to 40 μM. By using EPR spectroscopy we establish that they do not penetrate the cells with the exception of [Eu(L2)]+ .

The lanthanide(iii) complexes (Gd, Eu, Dy, and Yb) of DOTA tris(amide) and bis(amide) derivatives (L1 and L2) featuring one redox active TEMPO arm were prepared. Ligand L2 harbours an alkyne fragment for further functionalization. The X-ray crystal structure of ligand L2 in complexation with Na+ was solved. The complexes showed in their CV one oxidation wave (0.26-0. 34 V vs. Fc+/Fc) due to an oxoammonium/nitroxide redox couple and a broad reduction corresponding to the nitroxide/hydroxylamine system. The Eu complexes demonstrated the presence of one water molecule in their coordination sphere. The nitroxide complexes were characterized by EPR spectroscopy, showing the typical 3-line pattern in the high temperature regime, which is quenched upon the addition of ascorbate (reduction into hydroxylamine). In their nitroxide form, the complexes show essentially no CEST peak. Conversely, the reduced complexes demonstrate a 12% CEST peak at 51 ppm, corresponding to the metal bound water molecule. Fast exchange precluded the CEST activity for the amide protons. All the complexes proved to be essentially non-toxic for M21 cells at concentrations up to 50 μM.

The lanthanide complexes EuL3, GdL3, YbL3 and LuL3 of the N,N'-bis(2-hydroxy-di-3,5-tert-butylphenyl)amine were prepared. The X-Ray crystal structures of GdL3 and LuL3 demonstrated a nine-coordinate sphere with three ligand molecules under their anionic diamagnetic form (Cat-N-BQ)-. The complexes showed three oxidation events (Eox11/2 = 0.15-0.16 V, E1/22 = 0.51-55 V, and E1/23 = 0.75-0.78 V vs. Fc+/Fc) via cyclic voltammetry, corresponding to the successive oxidation of the aminophenolate moeities to iminosemiquinone species. The complexes GdL3 and YbL3 were characterized by EPR spectroscopy, allowing for the determination of the zero field splitting (ZFS) parameters in the first case. The monocations (LnL3)+ and monoanions (LnL3)- were electrochemically generated (Ln = Eu, Gd, Yb, Lu), as well as the dications YbL32+ and LuL32+. The spins are antiferromagnetically exchange coupled in the diradical species LuL32+ (|D| = 260 MHz, E = 0). All the complexes (incl. neutral) possess a strong absorption band in the NIR region (730-840 nm, ε > 19 mM-1 cm-1) corresponding to ligand-based transitions.

The DOTA-based ligand H3L (5) appended with a pro-nitroxide moiety has been synthesized. The europium and ytterbium complexes 5Ln show metal-centred luminescence. They react with ROS in aqueous media to give a transient iminonitroxide and a stable nitronylnitroxide radical authenticated by EPR, with change in luminescence.

European Water Framework Directive is enforced in five tropical French Oversea Territories where mangroves are present. Developing bioindication tools to support the ecosystem-based management approach of the Directive is needed. A series of expert workshops was organized and led to the proposal of a strategy and of an applied research program to develop bioindication tools. The proceedings of the workshops are presented as a case study, as this is the first time such an integrative ecosystem-based approach is proposed in mangroves, combining structural and functional aspects, from forest structure to benthic community functioning.

Despite the low tree diversity and scarcity of the understory vegetation, the high morphological plasticity of mangrove trees induces, at the stand level, a very large variability of forest structures that need to be mapped for assessing the functioning of such complex ecosystems. Fully constrained linear spectral unmixing (FCLSU) of very high spatial resolution (VHSR) multispectral images was tested to fine-scale map mangrove zonations in terms of horizontal variation of forest structure. The study was carried out on three Pleiades-1A satellite images covering French island territories located in the Atlantic, Indian, and Pacific Oceans, namely Guadeloupe, Mayotte, and New Caledonia archipelagos. In each image, FCLSU was trained from the delineation of areas exclusively related to four components including either pure vegetation, soil (ferns included), water, or shadows. It was then applied to the whole mangrove cover imaged for each island and yielded the respective contributions of those four components for each image pixel. On the forest stand scale, the results interestingly indicated a close correlation between FCLSU-derived vegetation fractions and canopy closure estimated from hemispherical photographs (R2 = 0.95) and a weak relation with the Normalized Difference Vegetation Index (R2 = 0.29). Classification of these fractions also offered the opportunity to detect and map horizontal patterns of mangrove structure in a given site. K-means classifications of fraction indeed showed a global view of mangrove structure organization in the three sites, complementary to the outputs obtained from spectral data analysis. Our findings suggest that the pixel intensity decomposition applied to VHSR multispectral satellite images can be a simple but valuable approach for (i) mangrove canopy monitoring and (ii) mangrove forest structure analysis in the perspective of assessing mangrove dynamics and productivity. As with Lidar-based surveys, these potential new mapping capabilities deserve further physically based interpretation of sunlight scattering mechanisms within forest canopy.

Amyloid fibres attract considerable interest due to their biological role in neurodegenerative diseases and their potential as functional biomaterials. Here, we describe an intrinsic signal of amyloid fibres in the near-infrared range. When combined with their recently reported blue luminescence, it paves the way towards new blueprints for the label-free detection of amyloid deposits in in vitro and in vivo contexts. The blue luminescence allows for staining-free characterization of amyloid deposits in human samples. The near-infrared signal offers promising prospects for innovative diagnostic strategies for neurodegenerative diseases—to improve medical care and for the development of new therapies. As a proof of concept, we demonstrate direct detection of amyloid deposits within brains of living, aged mice with Alzheimer’s disease using non-invasive and contrast-agent-free imaging. Ultraviolet–visible–near-infrared optical properties of amyloids open new research avenues for amyloidosis as well as for next-generation biophotonic devices. Two optical signatures of amyloid fibres—luminescence in the blue and a near-infrared signal, which can be observed in in vitro and in vivo tissues—are reported. The findings allow for staining-free characterization of amyloid deposits in human samples and could open the door to innovative diagnostic strategies for neurodegenerative diseases.

Aim: Seasonally dry tropical forest (SDTF) of the Caribbean Islands (primarily West Indies) is floristically distinct from Neotropical SDTF in Central and South America. We evaluate whether tree species composition was associated with climatic gradients or geographical distance. Turnover (dissimilarity) in species composition of different islands or among more distant sites would suggest communities structured by speciation and dispersal limitations. A nested pattern would be consistent with a steep resource gradient. Correlation of species composition with climatic variation would suggest communities structured by broad-scale environmental filtering. Location: The West Indies (The Bahamas, Cuba, Hispaniola, Jamaica, Puerto Rico, US Virgin Islands, Guadeloupe, Martinique, St. Lucia), Providencia (Colombia), south Florida (USA) and Florida Keys (USA). Taxon: Seed plants-woody taxa (primarily trees). Methods: We compiled 572 plots from 23 surveys conducted between 1969 and 2016. Hierarchical clustering of species in plots, and indicator species analysis for the resulting groups of sites, identified geographical patterns of turnover in species composition. Nonparametric analysis of variance, applied to principal components of bioclimatic variables, determined the degree of covariation in climate with location. Nestedness versus turnover in species composition was evaluated using beta diversity partitioning. Generalized dissimilarity modelling partitioned the effect of climate versus geographical distance on species composition. Results: Despite a set of commonly occurring species, SDTF tree community composition was distinct among islands and was characterized by spatial turnover on climatic gradients that covaried with geographical gradients. Greater Antillean islands were characterized by endemic indicator species. Northern subtropical areas supported distinct, rather than nested, SDTF communities in spite of low levels of endemism. Main conclusions: The SDTF species composition was correlated with climatic variation. SDTF on large Greater Antillean islands (Hispaniola, Jamaica and Cuba) was characterized by endemic species, consistent with their geological history and the biogeography of plant lineages. These results suggest that both environmental filtering and speciation shape Caribbean SDTF tree communities.

One-electron oxidation of the lanthanide complexes affords phenoxyl radical species. Radical formation is accompanied by a quenching of the metal-based luminescence.

Despite low plant diversity and structural simplicity, mangroves offer various ecosystem services to local human communities, including sheltering coastal social-ecological systems from high-energy storm damage. The expected increasing intensity of hurricanes due to climate change raises questions concerning the capacity of mangroves to resist and recover from such disturbances. Herein, this study contributes to a better understanding of (1) the relation between storm intensity and damage to mangrove vegetation, (2) the contributions of species-specific as well as stand-specific components of mangrove vegetation to ecosystem resistance, and (3) the recovery of pre-hurricane forest structure through time. The first two issues have been addressed using a stand-level approach implemented at two east Caribbean mangrove sites in response to three storm events. The third was addressed through a 23-yr survey of forest recovery following the passage of a high-energy storm across one of the two study sites. Generally, hurricane damage was primarily controlled by wind velocity, followed by the hydro-geo-morphic context of mangrove forests and species-specific composition, respectively. The relationship between damage to trees and wind velocity evidenced a sigmoidal trend, with a maximum slope at a wind velocity averaging 130 and 180 km/h for higher vs. lower canopy stands, respectively. The red mangrove , Rhizophora mangle, was significantly less resistant to hurricane damage than was the black mangrove , Avicennia germinans. Unlike the fringe and scrub stands, inner, tall-canopy stands fully recovered by the end of the study (23 yr). These stands were more resilient because of their growth performances. Finally, the time for east Caribbean mangroves to recover from high-energy storms seems to fall within the range of the average return time of such disturbances. This may prevent such ecosystems from ever reaching a steady state.

The ligand H3L and its corresponding tris(phenolato) lanthanide complexes L-Tb, L-Gd, L-Yb and L-Lu were synthesized. The X-Ray crystal structures demonstrated a monocapped octahedron environment of the lanthanide ion, with exclusion of all solvent molecules from the coordination sphere due to the protection by the tertbutyl groups. The coordination bond distances followed the lanthanide contraction, with Ln-O bond lengths in the range 2.148-2.217 angstrom and Ln-N-imine bond lengths in the range 2.405-2.535 angstrom. Each of the complexes showed three one-electron oxidation processes. These potentials changed as a function of the lanthanide due to the difference in size of the metal ions. Both chemical and electrochemical oxidations of these complexes permitted the one-electron oxidised species to be generated. They all show a sharp absorption band at around 420 nm in their UV-Vis spectra, which demonstrated phenoxyl radical formation. Consistently, the radical species L-Lu+ displays a resonance at g = 2.001 in its EPR spectrum. The other cations are EPR-silent or difficult to detect due to magnetic interactions, confirming the proximity of the phenoxyl radical to the metal centre. For both L-Lu+ and L-Yb+ DFT calculations predict the radical to be delocalized over the three arms. The L-Tb and L-Yb complexes experienced a quenching of the luminescence upon oxidation to the radical species whereby the quenching of up to 83% in the visible region and 93% in the NIR was observed.

The reversible oxidation of coordinated phenolates into phenoxyl radicals results in a dramatic quenching (>95%) of the luminescence of the f metal ion.

This work has been performed by a French national consortium within the framework of the national project Tandem, with aim to improve knowledge about tsunami risk on the French coasts. Work-package #1 of this project was the opportunity to build a database of benchmark cases to assess the capabilities of 18 codes, solving various set of equations with different numerical methods. 14 test cases were defined from the existing literature with validation data from reference simulations, theoretical solutions or lab experiments. They cover the main stages of tsunami life: 1) generation, 2) propagation, 3) run-up and submersion, and 4) impact. For each case several of the numerical codes were compared in order to identify the forces and weaknesses of the models, to quantify the errors that these models may induce, to compare the various modelling methods, and to provide users with recommendations for practical studies. In this paper, 3 representative cases are selected and presented with an analysis of the results.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.