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Development of Mg-ion batteries as advanced electrochemical energy storage systems relies on the design and discovery of high-voltage positive electrode (cathode) materials. To date, a variety of sulfide cathodes have been reported (e.g., MgxMo6S8, MgxTi2S4, etc.), but the voltages of these materials are too low to prepare a high energy density Mg cell. Theoretical computations predicted that MgxCr2S4 operating with the high-voltage Cr3+/4+ redox couple would serve as a suitable cathode candidate, but experimental attempts to extract Mg2+ from the lattice have been largely unsuccessful. We show that reversible electrochemical activity within a thiospinel framework (AB2S4) relies on a redox-active transition metal present in the B site; otherwise, anionic redox activity triggers decomposition of the spinel structure. Since Cr and S states are highly coupled in MgCr2S4, the Cr3+/4+ redox couple is inaccessible so that reversible (de)intercalation of Mg2+ cannot occur and charging leads to dissolution of the active material. These findings point to an insufficiency in the screening criteria previously used to identify MgCr2S4 as a promising Mg cathode. Thus, a computable descriptor based on the electronic structure of the discharged material is proposed to predict the prevalence of cation vs anion redox and improve future surveys of potential candidates. It is unlikely that the high-voltage Cr redox couple will be accessible to oxidation in the presence of sulfur within the restrictions of a spinel framework; however, it is possible that a suitable layered MgxCrS2 structure could serve as a reversible high-voltage Mg cathode.

Aim: Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location: Tropical and subtropical moist forests. Time period: Current. Major taxa studied: Palms (Arecaceae). Methods: We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co-occurring non-palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results: On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long-term climate stability. Life-form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non-tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above-ground biomass, but the magnitude and direction of the effect require additional work. Conclusions: Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.

The paper is related to energy absorptive properties of additively manufactured metallic cellular structures. The samples of Honeycomb, Auxetic, rhomboidal Lattice and a regular Foam are subjected to a dynamic compression due to the blast tests. The cuboidal samples are manufactured by the Direct Metal Laser Sintering (DMLS) method using AlSi10Mg aluminium powder. The experimental tests are performed by means of an Explosive Driven Shock Tube (EDST). The measured results of the transmitted forces in relation to the shortening of the samples allow to analyse the deformation processes of each selected geometry. In addition, the evaluation of the structural responses leads to identification of the structure properties, such as the equivalent stress over equivalent strain or the energy absorption per a unit of mass. Moreover, the process of compression is modelled numerically using the explicit code LS-DYNA R9.0.1. The obtained simulations provide the complete analysis of the experimentally observed mechanisms.

L'analyse triadique partielle (ATP), introduite en écologie par THIOULOUSE et CHESSEL (1987), est reprise dans cet article. Le principe de la méthode est présenté de façon simplifiée afin de faciliter son usage. Cette méthode permet de faire les analyses en composantes principales (ACP) simultanées et coordonnées de plusieurs tableaux de relevés faunistiques ou mésologiques effectués, par exemple, dans différentes localités de façon répétée dans le temps. Dans ce cas, l'ATP permet de trouver une structure spatiale stationnelle commune à tous les tableaux (dates d'échantillonnage) et d'en étudier la stabilité temporelle. Pour cela, la méthode s'appuie sur la recherche d'une moyenne de tableaux appelée compromis et sur la reproductibilité du compromis par chacun des tableaux initiaux. Nous présentons également l'analyse d'une série de tables de contingence (FOUCART, 1978) qui, dans le même contexte expérimental, permet d'utiliser une stratégie d'analyse factorielle des correspondances (AFC) plutôt qu'une stratégie d'ACP. Nous illustrons le potentiel de ces méthodes multitableaux à l'aide d'un exemple en hydrobiologie en soulignant leur capacité à décrire une évolution temporelle de structures spatiales par rapport à une référence commune.

Les peuplements piscicoles de 35 stations des régions Languedoc-Roussillon et Provence-Alpes-Côte d'Azur ont été échantillonnés sur quatre années entre 1993 et 1996, dans le cadre du Réseau Hydrobiologique et Piscicole mis en place par le Conseil Supérieur de la Pêche. Pour analyser ces données de type espèces-stations-dates, nous avons utilisé deux méthodes d'analyse multitableaux : l'analyse triadique partielle (THIOULOUSE et CHESSEL, 1987 ; BLANC et al., 1998) et l'Analyse Factorielle des Correspondances de FOUCART (1978, 1983). Quelle que soit la méthode utilisée, une structure spatiale espèces-stations commune aux différentes dates a été mise en évidence. La première oppose principalement des stations à truite aux stations à cyprinidés et révèle un double effet de régionalisation. La deuxième a mis en évidence une structure amont-aval proche de celles des schémas ichtyologiques de référence (HUET, 1954 ; VERNEAUX, 1973, 1981). L'étude temporelle des structures autour de la structure moyenne a montré une forte stabilité durant la période étudiée.

While various bariatric surgeries are commonplace in obesity medicine for humans, these techniques have not been commonly used in veterinary medicine. A technique used in humans consists in endoscopically placing an intragastric balloon. The intragastric balloon takes volume in the stomach causing a feeling of satiety and reducing food intake. A 57.6 kg, 9‐year‐old neutered female Labrador dog with chronic hypothyroidism was presented for overweight management. Combined levothyroxine treatment and dietary management with specific alimentation for obesity had failed to control overweight. An intragastric balloon was placed endoscopically in the stomach to allow the reduction of the gastric capacity and resulted in effective weight loss. The dog weight decreased to 40.9 kg at the time of intragastric balloon removal 198 days after placement. Further research including a larger sample size and long term follow‐up is required to establish safety and effectiveness of this procedure. [ABSTRACT FROM AUTHOR]