A formal classification of the Lygeum spartum vegetation of the Mediterranean Region

Aims We examined local and regional contribution on the grasslands dominated by Lygeum spartum from Southern Europe and North Africa to produce a formalised classification of this vegetation and to identify main factors driving its plant species composition. Location Mediterranean Basin and Iberian Peninsula. Methods We used a dataset of 728 relevés, which were resampled to reduce unbalanced sampling effort, resulting in a dataset of 568 relevés and 846 taxa. We classified the plots by TWINSPAN, interpreted the resulting pools, and used them to develop formal definitions of phytosociological alliances characterised by L. spartum vegetation. The definitions were included in an expert system to assist automatic vegetation classification. We related the alliances to climatic factors and described their biogeographical features and ecological preferences. The floristic relationships between these alliances were analysed and visualised using distance‐based redundancy analysis. Results We defined eleven alliances of L. spartum vegetation, including the newly described Launaeo laniferae‐Lygeion sparti from SW Morocco and the Noaeo mucronatae‐Lygeion sparti from the Algerian highlands and NE Morocco. Biogeographical, climatic, and edaphic factors were revealed as putatively driving the differentiation between the alliances. The vegetation of clayey slopes and inland salt basins displayed higher variability in comparison with those of coastal salt marshes. Main conclusions The most comprehensive formal classification, accompanied by an expert system, of the L. spartum vegetation was formulated. The expert system, containing the formal definitions of the phytosociological alliances, will assist in identification of syntaxonomic position of new datasets

Species pools along contemporary environmental gradients represent different levels of diversification

Aim - Within a region, different habitat types are characterized by different species and some habitat types have higher species diversities than others. Different habitat types are also characterized by different phylogenetic clades. However, it is not known whether – within a given region – some habitat types have species pools that are more phylogenetically diversified than others. We investigated whether species pools in contemporary habitat types represent different levels of diversification of angiosperms and, if so, whether these differences correlate with particular environmental factors. We tested these relationships in a region of recent geological origin possessing a comparatively young flora, and compared the result with standard analyses of species diversity. Location The Netherlands. Methods - We studied angiosperms across the full range of habitat types present in the Netherlands. We characterized levels of diversification represented in species pools within each of these habitat types with respect to (1) taxonomic diversification, i.e. the rate of increase of richness across taxonomic ranks (relative to a null expectation for a given species richness), and (2) cladogenic diversification, i.e. the average cladogenic distance of species from the root of a phylogenetic tree of the species pool within a given region. Results - Species pools of different habitat types represented different levels of taxonomic and cladogenic diversification. These differences were strongly correlated with the environmental characteristics of the habitat type. Greater levels of taxonomic diversification were represented in the species pools of relatively dry and open habitat types. Greater levels of cladogenic diversification were represented in habitats with both dry and weakly acidic soils. The relationship between environmental factors and taxonomic and cladogenic diversification (r2 = 0.88 and 0.76, respectively) was stronger than that between environmental factors and species richness (r2 = 0.34). Main conclusions - Within a region, species resulting from particularly high rates of diversification accumulated in particular habitat types. These habitat types represent specific contemporary abiotic environments and have a tighter relationship with levels of diversification than with species richness

Impact de la qualité lipidique des formules infantiles sur les fonctions cérébrales dans un modèle d’allaitement artificiel chez le raton : effets des lipides laitiers et de la supplémentation en acides docosahexaénoïque et arachidonique

International audience(A. Deglaire) Introduction et but de l'étude Le lait maternel est l'aliment idéal pour le nouveau-né, particulièrement chez le prématuré (OMS, 2015). Il peut être pas-teurisé pour des raisons sanitaires, ce qui peut notamment modifier les cinétiques globales de protéolyse [1–3]. L'objectif de cette étude était d'évaluer l'impact de la pasteurisation du lait maternel sur les cinétiques de libération des produits intermédiaires de protéolyse, c'est-à-dire les peptides. Matériel et méthodes Douze enfants prématurés hospitalisés (30,0 ± 1,0 semaines d'aménorrhée ; 1,4 ± 0,3 kg), nourris par sonde gastrique, ont participé à cette étude randomisée (NCT02112331). Sur 6 jours consécutifs, chaque enfant recevait le même jour deux repas tests à base de lait maternel cru ou pasteurisé. Les effluents gastriques étaient collectés en double à 35, 60 ou 90 min. Le lait avant digestion et les effluents étaient analysés semi-quantitativement en spec-trométrie de masse tandem, après séparation par nanochromatographie. Après transformation des données et application pour chaque peptide d'un modèle linéaire mixte (facteurs : temps, repas, repas × temps, jour [temps], poids corpo-rel, teneur en protéines du lait et sujet), une classification hiérarchique ascendante était réalisée sur les coefficients d'interaction « repas × temps » et des groupes de peptides étaient ainsi identifiés (logiciel R). Résultats La classification de 1579 peptides (six à 51 acides aminés ; caséine-: 58 %, lactoferrine : 10 %), mettait en évidence cinq groupes, caractérisé

Potent and Selective Inhibition of Histone Deacetylase 6 (HDAC6) Does Not Require a Surface-Binding Motif

Hydroxamic acids were designed, synthesized, and evaluated for their ability to selectively inhibit human histone deacetylase 6 (HDAC6). Several inhibitors, including compound <b>14</b> (BRD9757), exhibited excellent potency and selectivity despite the absence of a surface-binding motif. The binding of these highly efficient ligands for HDAC6 is rationalized via structure–activity relationships. These results demonstrate that high selectivity and potent inhibition of HDAC6 can be achieved through careful choice of linker element only

Discovery of the First Histone Deacetylase 6/8 Dual Inhibitors

We disclose the first small molecule histone deacetylase (HDAC) inhibitor (<b>3</b>, BRD73954) capable of potently and selectively inhibiting both HDAC6 and HDAC8 despite the fact that these isoforms belong to distinct phylogenetic classes within the HDAC family of enzymes. Our data demonstrate that meta substituents of phenyl hydroxamic acids are readily accommodated upon binding to HDAC6 and, furthermore, are necessary for the potent inhibition of HDAC8

Potent and Selective Inhibition of Histone Deacetylase 6 (HDAC6) Does Not Require a Surface-Binding Motif

Hydroxamic acids were designed, synthesized, and evaluated for their ability to selectively inhibit human histone deacetylase 6 (HDAC6). Several inhibitors, including compound <b>14</b> (BRD9757), exhibited excellent potency and selectivity despite the absence of a surface-binding motif. The binding of these highly efficient ligands for HDAC6 is rationalized via structure–activity relationships. These results demonstrate that high selectivity and potent inhibition of HDAC6 can be achieved through careful choice of linker element only