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Solid-state lithium batteries are considered one of the most promising battery systems due to their high volumetric energy density and safety. Poly(ethylene oxide) (PEO) is the most commonly used solid polymer electrolyte in solid-state batteries. In this article, we introduce new polyphosphoester polymer electrolytes, which show improved flame retardant properties in comparison with PEO. For this purpose, new polyphosphoester copolymers were synthesized, including phosphoester, poly(ethylene glycol) (PEG) and UV cross-linkable vinyl units. Solid polymer electrolyte films based on polyphosphoester copolymers and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were prepared by curing under UV-light. The crystallinity present in the copolymers due to the PEG segment decreases with the amount of salt in the electrolyte, as seen by DSC. Solid polymer electrolytes based on polyphosphoester copolymers show ionic conductivity values as high as 2 × 10−4 S cm−1 at 70 °C. FTIR analysis showed that lithium cations complexed with phosphoester groups provoked an increase in the lithium transference number to 0.26 as compared to that of PEO 0.17. Pyrolysis flow combustion calorimetry (PCFC) or micro-calorimetry results demonstrated the improved flame retardancy of the polyphosphoesters in comparison to a reference PEO based polymer electrolyte. The selected polyphosphoester solid electrolyte was investigated in a solid-state lithium cell Li0/polymer electrolyte/LFP battery showing a specific capacity retention close to 80% and coulombic efficiency greater than 98% over 100 cycles at 70 °C.

International audience; Although old molecules, alkylating agents and platinum derivatives are still widely used in the treatment of various solid tumors. However, systemic toxicity and cellular resistance mechanisms impede their efficacy. Innovative strategies, including local administration, optimization of treatment schedule/dosage, synergistic combinations, and the encapsulation of bioactive molecules in smart, multifunctional drug delivery systems, have shown promising results in potentiating anticancer activity while circumventing such hurdles. Furthermore, questioning of the old paradigm according to which nuclear DNA is the critical target of their anticancer activity has shed light on subcellular alternative and neglected targets that obviously participate in the mediation of cytotoxicity or resistance. Thus, rethinking of the use of these pivotal antineoplastic agents appears critical to improve clinical outcomes in the management of solid tumors.

Due to their great modularity, ease of implementation, and atom economy, multicomponent reactions (MCRs) are becoming increasingly popular macromolecular engineering tools. In this context, MCRs suitable in polymer synthesis are eagerly searched for. This work demonstrates the potential of the Ugi-three component reaction (Ugi-3CR) for the design of polymers and, in particular, of poly(α-amino amide)s. A series of polymers containing amino and amido groups within their backbone were obtained through a one-pot process by reacting aliphatic or aromatic diamines, diisocyanides, and aldehydes. The impact of temperature, concentration, catalyst loading, and substrates on polymerization efficiency is discussed. A preliminary study on the thermal properties and the solution behavior of these poly(α-amino amide)s was carried out. An aliphatic-rich derivative notably showed some pH-responsiveness in water via protonation-deprotonation of its amino groups.

Polymer characterizations are often performed using mass spectrometry (MS). Aside from MS and different tandem MS (MS/MS) techniques, ion mobility–mass spectrometry (IM-MS) has been recently added to the inventory of characterization technique. However, only few studies have focused on the reproducibility and robustness of polymer IM-MS analyses. Here, we perform collisional and electron-mediated activation of polymer ions before measuring IM drift times, collision cross-sections (CCS), or reduced ion mobilities (K0). The resulting IM behavior of different activated product ions is then compared to non-activated native intact polymer ions. First, we analyzed collision induced unfolding (CIU) of precursor ions to test the robustness of polymer ion shapes. Then, we focused on fragmentation product ions to test for shape retentions from the precursor ions: cation ejection species (CES) and product ions with m/z and charge state values identical to native intact polymer ions. The CES species are formed using both collision induced dissociation (CID) and electron transfer dissociation (ETD, formally ETnoD) experiments. Only small drift time, CCS, or K0 deviations between the activated/formed ions are observed compared to the native intact polymer ions. The polymer ion shapes seem to depend solely on their mass and charge state. The experiments were performed on three synthetic homopolymers: poly(ethoxy phosphate) (PEtP), poly(2-n-propyl-2-oxazoline) (Pn-PrOx), and poly(ethylene oxide) (PEO). These results confirm the robustness of polymer ion CCSs for IM calibration, especially singly charged polymer ions. The results are also discussed in the context of polymer analyses, CCS predictions, and probing ion–drift gas interaction potentials.

Ion Mobility (IM) coupled to Mass Spectrometry (MS) has been used for several decades, bringing a fast separation dimension to the MS detection. IM-MS is a convenient tool for structural elucidation. The folding of macromolecules is often assessed with the support of computational chemistry. However, this strategy is strongly dependent on computational initial guesses. Here, we propose the analysis of the Collision Cross-Section (CCS) trends of synthetic homopolymers based on a fitting method which does not rely on computational chemistry a prioris of the three-dimensional structures. The CCS trends were evaluated as a function of the polymer chain length and the charge state. This method is also applicable to mobility trends. It leads to two parameters containing all information available through IM(-MS) measurements. One parameter can be interpreted as an apparent density. The second parameter is related to the shape of the ions and leads us to introduce the concept of trends with constant apparent density. Based on the two fitting parameters, a method for IM trend predictions is elaborated. Experimental deviations from the predictions facilitate detecting structural rearrangements and three-dimensional structure differences of the cationized polymer ions. This leads for instance to an easy identification and prediction of the presence of different polymer topologies in complex polymer mixtures. The classification of predicted trends could as well allow for software-assisted data processing. Finally, we suggest the link between the CCS trends of homopolymers and those obtained from (monodisperse) biomolecules to interpret potential folding differences during IM-MS studies.

The purpose of this article is to shed light on the “darker” side of language in cross-cultural communication and explore ways that it can be addressed, using a dialogical approach. Bakhtin’s dialogical perspective conceptualizes sensemaking as the co-construction of meaning through interconnected utterances (“addressivity” and “responsivity”), multivoicedness (“polyphony”), and multiple speaking styles (“heteroglossia”). We use these concepts to analyze the social processes underlying linguistic hegemony and language-based in-group behavior in a case study of the performance of six multicultural teams at an American subsidiary in France. We found that although dialogical practices proved to be effective in deterring the emergence of the dark side of language, the lack of a dialogical mindset prevailed in four of the six teams. These findings point to the need for cross-cultural management policies which reward addressivity, polyphony, and heteroglossia while penalizing team members who use their superior language skills to dominate others.

International audience; Au Sahel, l’élevage pastoral valorise un milieu extrême. Alors qu’il est accusé d’émettre trop de gaz à effet de serre par kilogramme de lait ou de viande produit, une recherche menée au Sénégal montre que les territoires pastoraux peuvent en réalité avoir un bilan carbone neutre : les émissions d’origine animale sont compensées par la séquestration de carbone dans les sols et la végétation. Ces résultats ont été obtenus par une méthode d’évaluation originale, dite écosystémique : elle intègre l’utilisation du territoire pastoral dans son ensemble, en fonction des saisons et des lieux investis par les troupeaux. Ces résultats incitent à revoir à la baisse les normes actuelles de calcul du comportement alimentaire et des émissions de méthane issu de la digestion des ruminants. D’autres implications sont envisageables, comme améliorer le bilan carbone par des pratiques locales spécifiques et valoriser ces espaces sur le marché du carbone. Préserver ce mode d’élevage est aussi une des voies pour générer du développement et contribuer à sécuriser ces régions.

International audience; Vitis vinifera is affected by many diseases every year, depending on causal agents, susceptibility of cultivars, and climate region. Some are caused by a single agent, such as gray mold caused by Botrytis cinerea or powdery mildew caused by Erysiphe necator. Others result from the actions of a complex of pathogens such as grapevine trunk diseases (GTDs). GTDs are presently among the most devastating diseases in viticulture worldwide because both the economic losses and the long-term sustainability of vineyards are strongly affected. The complexity of GTDs results from the diversity of associated fungi, the undetermined period of latency within the vine (asymptomatic status), the erratic foliar symptom expression from one year to the next, and, probably correlated with all of these points, the lack of efficient strategies to control them. Distinct methods can be beneficial to improve our knowledge of GTDs. In vitro bioassays with cell suspensions, calli, foliar discs, full leaves, or plantlets, and in vivo natural bioassays with cuttings, grafted plants in the greenhouse, or artificially infected ones in the vineyard, can be applied by using progressive integrative levels of in vitro and in vivo, depending on the information searched. In this review, the methods available to understand GTDs are described in terms of experimental procedures, main obtained results, and deliverable prospects. The advantages and disadvantages of each model are also discussed.

International audience; Domestic species such as cattle (Bos taurus taurus and B. t. indicus) represent attractive biological models to characterize the genetic basis of short term evolutionary response to climate pressure induced by their post-domestication history. Here, using newly generated dense SNP genotyping data, we assessed the structuring of genetic diversity of 21 autochtonous cattle breeds from the whole Mediterranean basin and performed genome-wide association analyses with covariables discriminating the different Mediterranean climate sub-types. This provided insights into both the demographic and adaptive histories of Mediterranean cattle. In particular, a detailed functional annotation of genes surrounding variants associated with climate variations highlighted several biological functions involved in Mediterranean climate adaptation such as thermotolerance, UV protection, pathogen resistance or metabolism with strong candidate genes identified (e.g. NDUFB3, FBN1, METTL3, LEF1, ANTXR2 and TCF7). Accordingly, our results suggest that main selective pressures affecting cattle in Mediterranean area may have been related to variation in heat and UV exposure, in food resources availability and in exposure to pathogens, such as anthrax bacteria (Bacillus anthracis). Furthermore, the observed contribution of the three main bovine ancestries (indicine, European and African taurine) in these different populations suggested that adaptation to local climate conditions may have either relied, on standing genomic variation of taurine origin or adaptive introgression from indicine origin, depending on the local breed origins. Taken together, our results highlight the genetic uniqueness of local Mediterranean cattle breeds and strongly support conservation of these populations

International audience; This paper explores an original approach in which greenhouse gas (GHG) emissions and carbon (C) accumulation are assessed monthly and at landscape scale to account for the highly seasonal monsoon climate and the mobility of pastoral herds that characterize West African pastoral ecosystems. The study was conducted in northern Senegal, in the service area of the Widou Thiengoly borehole, a circular zone of 706 km(2) centered on the borehole. The C balance was calculated using an ecosystem approach, i.e. taking all main sources of GHG emissions and C sinks of the ecosystem, not only anthropogenic sources, into account. The annual C balance of the pastoral ecosystem was -0.04 +/- 0.01 tC-eq.ha(-1).year(-1), showing that total GHG emissions were mitigated by C accumulation in trees, soil and livestock. The C balance varied considerably with the seasons, with a positive monthly balance in the wet season, from July to October (+ 0.58 tC-eq.ha(-1).month(-1)) and a negative monthly balance in the cold dry season from November to February and the hot dry season from March to June (- 0.57 and -0.05 tC-eq.ha(-1).month(-1) respectively). Care should be taken when generalizing these results, which were obtained in a dry year, because of strong inter-annual variations in rainfall.

Agriculture development in sub-Saharan Africa is characterized by two important tendencies: (1) a strong degradation of the natural forage resources exploited by pastoralism due to excess and uncontrolled stocking density linked to increasing demographic pressure and (2) development and intensification of arable cropping sectors within large irrigated perimeters based on mono-cropping systems directly linked with market pressure but leading to important negative impacts on environments. In between these two systems, there is space for development of more integrated crop-livestock systems based on a network of smallholder farms and susceptible to profit from synergies provided by diversification of production systems. The development of a local dairy production along the Senegal River, based on milk collection from a network of poor smallholder producers, is a relevant example of the accuracy of such a local integration across specialized sectors. The development of a pivotal forage resource based on alfalfa associated with arable cropping system should allow strong local synergies for (1) improving nutrition quality of local peoples by both nutritional complement production with leaf extracts and local dairy industry expansion and (2) improving agronomic and environmental performances of arable cropping systems. But beyond the technological, agronomic, and environmental benefits potentially provided by this integrated system, the socioeconomic conditions for its emergence and adoption have to be analyzed and promoted, which require further important studies.

The polymerization of cyclic phosphates to poly(phosphoester)s, PPEs, is optimized for chip-based microreactors under continuous flow conditions. The anionic ring-opening polymerization of 2-isobutyoxy-2-oxo-1,3,2-dioxaphospholane (iBP) via the use of two organocatalytic systems allowed to polymerize to nearly quantitative monomer conversion within 10 or 3 min, respectively at a reaction temperature of 40 °C. Further, the optimized polymerization protocol was applied to 2-butenoxy-2-oxo-1,3,2-dioxaphospholane (BP) which yields a polymer that carries an alkene functionality per monomer repeating unit. This material can be postmodified in an UV-induced radical thiol–ene reaction, which was also shown to proceed with very high efficiency under UV-flow conditions. Eventually, both reactions were coupled in a two-stage reactor setup, showing that the thermally-activated polymerization can be coupled with high efficiency to the UV-activated post-polymerization modification reaction. The introduced reactor setup can in the future be used to produce and screen a broad variety of functional PPE materials with various functionalities and physical properties.

Poly(ethylene oxide)-b-polyphosphoester amphiphilic block copolymers are known to self-assemble into polymer micelles when dissolved in water. This work aims at reporting on the improvement of the stability of the micelles at high dilution by crosslinking the hydrophobic polyphosphoester micellar core. Typically, an unsaturated alkene side-chain was introduced onto the cyclic phosphate monomer according to a one-step reaction followed by its organocatalyzed polymerization initiated by a poly(ethylene oxide) macroinitiator. This strategy avoids the use of any organometallic compounds in order to facilitate the purification and meet the stringent requirements of biomedical applications. After self-assembly in water, the micelles were cross-linked by simple UV irradiation. These cross-linked micelles have then been loaded with doxorubicin to evaluate their potential as drug nanocarriers and monitor the impact of crosslinking on the release profile.

International audience; Long-term organic fertilizer (OF) application on agricultural soils is known to induce soil Cu and Zn contamination, along with pH and organic matter changes, which in turn alter the soil Cu and Zn availability. Our study was aimed at assessing Cu and Zn availability in long-term OF-amended soils by distinguishing the importance of increased contamination levels versus pH and organic matter changes in soil. Seventy-four soil samples were collected over time from fields corresponding to three soil types upon which no, mineral, or organic fertilization had been applied over a decade, and thus exhibited a gradient of Cu and Zn contamination, pH, and organic matter concentration. Soil Cu and Zn contamination (i.e. total and DTPA-extractable Cu and Zn concentration), soil solution chemistry (i.e. pH and dissolved organic matter concentration and aromaticity) and Cu and Zn availability (i.e. total concentration and free ionic activity in solution and DGT-available concentration in soil) levels were measured. The Windermere humic aqueous model (WHAM) was used to estimate Zn2+ activity and dissolved organic matter (DOM) binding properties in soil solution. Regardless of the soil type, organic fertilization increased Cu and Zn contamination in soil, in addition to the pH and the DOM concentration, aromaticity and binding properties in soil solution. The pH increase prompted a decrease in the total Zn concentration and Zn2+ activity in soil solution. The concomitant pH increase and DOM concentration, aromaticity and binding properties boosted the total Cu concentration but decreased the Cu2+ activity in soil solution. DGT-available Cu and Zn varied very little between the three fertilization modalities. Our results suggest that pH and DOM changes were able to regulate Cu and Zn availability in long-term OF amended soils by exerting a protective effect that offset the concomitant increase in soil Cu and Zn contamination.

The synthesis of aliphatic polyesters by the ring-opening polymerization of cyclic monoesters was discovered by Carothers in the 1930s. Since then, a plethora of catalysts and initiators have been discovered to promote this polymerization. Nowadays, steadily increasing attention is paid to organocatalysts and, among them, acids, bases, and H-bond donors and acceptors. Organocatalysts today available for the polymerization of medium size cyclic monoesters such as δ-valerolactone and ε-caprolactone will be reviewed. Special attention will be paid to dual catalysts capable of activating both the initiator and the monomer. The most efficient catalysts promote fast and selective ring-opening polymerization. The mechanism based either on ionic interactions, the establishment of H-bonds or nucleophilic activation will be discussed. The importance of ring size will be highlighted by the organocatalyzed polymerization of β-butyrolactone, γ-butyrolactone and pentadecalactone as a typical macrocyclic monoester.

National audience

Glioblastoma is the most frequent and aggressive primary malignant tumor of the central nervous system with a gloomy prognosis. Platinum derivatives and one among them, cisplatin, exhibited promising results when locally administered into the brain of glioblastoma bearing rats. Nanovectorization of anticancer agents through polymeric nanoparticles may even promote drug accumulation within cells, thus concentrating the drug efficiently at its target. Anchorage of gadolinium complexes on the corona of such smart drug delivery systems could further allow magnetic resonance imaging (MRI) monitoring of the nanoplatform biodistribution in the damaged parenchyma and its therapeutic benefit. For this purpose, a biocompatible amphiphilic triblock copolymer, made of degradable polyester and polycarbonate and bioeliminable polyethylene oxide (PEO), was synthesized by successive ring-opening polymerizations. After micellization in water, gadolinium complexes were grafted onto the PEO micelle corona and the carboxylate functions, located at the surface of the micelle's core, were able to cross-link with Pt(ii) complexes. A macromolecular prodrug was therefore recovered in which more than one third of the carboxylate functions were linked to a platinum atom. By this strategy, stable cisplatin cross-linked nanoparticles were formulated with a mean size in the range of 100.63 ± 12.04 nm consistent with biological investigations. Relaxometry measurements both in water and in plasma at 7 T, 25 °C, confirmed the intrinsic potential of these hybrid nanoparticles as alternative MRI contrast agents with a substantial increase in the r2/r1 ratio by a factor of 3.3 and 2.7, respectively, compared to the conventional low molar mass Gd-DTPA. As a result, their infusion within the striatum of glioblastoma-bearing mice resulted in a hypersignal on T2-weighted MR images that persisted over time. Ultimately, the formulated prodrug exhibited up to 50-fold increased accumulation in human glioblastoma cell lines and up to 32-fold enhanced subsequent Pt-DNA adduct formation in comparison with free cisplatin, thus supporting the potential of this innovative bimodal tool for further applications.

International audience; Ruminant livestock systems are significant sources of greenhouse gases (GHG). Livestock farming in regions with extreme climatic events have to face both scarcity and variability in feed resources. Herd mobility is a known major adaptation strategy to address seasonal availability of forage resources: it allows an increase in herd size, thereby improving labor productivity. The present study quantifies enteric methane (CH4) emissions from French Mediterranean sheep farming systems, focusing on the use of diversified pastoral feed resources, and developing a calculator (Diversity of feed REsources and Enteric Methane emissions, DREEM). The DREEM calculator was developed to estimate at the animal level enteric CH4 emissions (g/day) from empirical equations and be subsequently integrated, as a sub-table, into an economic and GHG (kg/year) balance model (Outil de Simulation du TRoupeau ovin ALaitant, OSTRAL) at the whole farm level. Several equations were taken from the literature to estimate enteric CH4 emissions in DREEM calculator. Nature of forage and feed, animal feeding levels and performance were referenced according to the animal feeding system and tables in France and taking into account the French Mediterranean area studied. DREEM was used to estimate enteric CH4 emissions from four sheep farming systems covering the main contrasting mobility and situations, from sedentary to highly mobile pastoral systems, in the French Mediterranean area. At the individual level, enteric CH4 emissions (g/ day) of ewes in the sedentary system were slightly higher than those of ewes in other systems. These differences were due mainly to differences in animal feeding level (intake / body weight) and feed resources characteristics. Overall, enteric CH4 emissions of ewes and rams were slightly lower than French national inventory estimates. When enteric CH4 emissions of lambs were expressed in g/kg of carcass, were lower in the less pastoral farming systems than in the other systems, because lambs' average daily gains were higher. In double transhuming farming systems, lambs late slaughtering age led to lamb's CH4 contribution of 15% vs 2-5% in the other systems. Flock management, which depends on land use and ownership, greatly contributed to these results.

On Reunion Island, grassland is the second agricultural land cover. Grasslands are present in the different ecological contexts of the island (from tropical at sea level to temperate climate on the mountain area). The fertilisation inputs are quite high. The long-term impacts of fertilisation on the vegetation have been studied mainly for temperate grasslands and impacts on tropical grasslands are not well known. The species pool is different in the diverse climates. The functional trait approach allows us to compare the dynamics of communities with different species. We studied the impact of fertilisation (quantity and type of inputs) on grassland communities along a climatic gradient. Since 2004, ten different treatments of fertilisation with three replicates (organic and/or mineral inputs from 0 to 600 kg N ha -1) were applied on grassland in three different sites of the western part of Reunion Island (tropical site, temperate site and intermediate site). Three functional traits were measured: the specific leaf area (SLA), leaf dry matter content (LDMC) and vegetative height (H) in 2016. From these trait values, different variables were calculated (functional diversity, intraspecific variability indicators, etc.) and were compared between the different treatments and sites. The functional trait value was different between the three sites. The fertilisation affected only a few functional traits. These impacts were more important in the temperate climate than in the tropical one. This work contributes to our understanding of the long-term impact of fertilisation on the flora composition and can be used to propose adapted management of fertilisations (type or quantity).

International audience; The feeding behavior and fodder intake of cattle, sheep and goats grazing semi-arid sub-Saharan Africa rangelands in Senegal was studied over a one-year cycle. The objective of the study was to improve the assessment of fodder intake by livestock grazing rangelands in semi-arid sub-Saharan Africa, The study was conducted in the service area of a borehole that includes 354 pastoral settlements and a total of 11,000 cattle and 1800 small ruminants. The grazing behavior of five steers was monitored monthly. Their forage intake was estimated every month from hand plucking simulations of all the bites of forage taken by the steers 24 h out of 48. The feces they excreted during the day were collected in fecal bags. Near infrared spectrum (NIRS) images were used to analyze 80 samples of these feces, and the data were then added to an existing reference data set to predict fodder intake and digestibility using NIBS. The complete and contextualized data base was then used to predict the daily fodder intake and its digestibility by cattle, sheep and goats whose fresh feces were systematically and randomly sampled every month in the study area (768 samples). Annual means of the daily dry matter fodder intake were 68.4 +/- 6.4 g/kg LW0.75 or 17.2 +/- 1.7 g/kg LW for cattle, 73.1 +/- 5.3 g/kg LW07.5 or 34.3 +/- 2.8 g/kg LW for sheep, and 74.7 +/- 8.7 g/kg LW0.75 or 37.1 +/- 4.4 g/kg LW for goats. The annual mean organic matter digestibility of grazed fodder was higher for goats (67.4 +/- 3.9%) than for sheep (64.1 +/- 3.2%) and cattle (59.3 +/- 3.8%). The seasonal variations in diet digestibility were bigger for cattle than for sheep, and smaller for goats. The standard reference used to assess livestock fodder intake in tropical Africa relies on a fixed daily intake rate per unit live weight of 25 g/kg LW. Our results show that this method overestimates (+ 45%) intake by cattle, especially in the dry season, and underestimates intake by small ruminants (-24%). Alternative assessment methods are proposed either relying on a single standard annual intake per metabolic weight unit for all ruminant species, 73 g/kg LW0.75 per day, or on separate annual intake norms per live weight unit for cattle (18 g/kg LW per day) and small ruminants (34 g/kg LW per day). In both cases, modulations (+/- 12%) of the norm are proposed for use in the wet and dry season.

International audience; Glioblastoma is the most frequent and aggressive primary malignant tumor of the central nervous system with a gloomy prognosis. Platinum derivatives and one among them, cisplatin, exhibited promising results when locally administered into the brain of glioblastoma bearing rats. Nanovectorization of anticancer agents through polymeric nanoparticles may even promote drug accumulation within cells, thus concentrating the drug efficiently at its target. Anchorage of gadolinium complexes on the corona of such smart drug delivery systems could further allow magnetic resonance imaging (MRI) monitoring of the nanoplat-form biodistribution in the damaged parenchyma and its therapeutic benefit. For this purpose, a biocom-patible amphiphilic triblock copolymer, made of degradable polyester and polycarbonate and bioelimin-able polyethylene oxide (PEO), was synthesized by successive ring-opening polymerizations. After micelli-zation in water, gadolinium complexes were grafted onto the PEO micelle corona and the carboxylate functions, located at the surface of the micelle's core, were able to cross-link with Pt(II) complexes. A macromolecular prodrug was therefore recovered in which more than one third of the carboxylate functions were linked to a platinum atom. By this strategy, stable cisplatin cross-linked nanoparticles were formulated with a mean size in the range of 100.63 ± 12.04 nm consistent with biological investigations. Relaxometry measurements both in water and in plasma at 7 T, 25 °C, confirmed the intrinsic potential of these hybrid nanoparticles as alternative MRI contrast agents with a substantial increase in the r 2 /r 1 ratio by a factor of 3.3 and 2.7, respectively, compared to the conventional low molar mass Gd-DTPA. As a result, their infusion within the striatum of glioblastoma-bearing mice resulted in a hypersignal on T 2-weighted MR images that persisted over time. Ultimately, the formulated prodrug exhibited up to 50-fold increased accumulation in human glioblastoma cell lines and up to 32-fold enhanced subsequent Pt-DNA adduct formation in comparison with free cisplatin, thus supporting the potential of this innovative bimodal tool for further applications.

Le recyclage de la biomasse végétale et animale joue un rôle central dans le fonctionnement des systèmes agro-sylvopastoraux. En Afrique de l’Ouest, la variabilité des précipitations impacte les pratiques de gestion de cette biomasse pour nourrir les hommes, le bétail, le sol et les plantes. Cette étude décrit un modèle d’action conceptuel basé sur des règles ≪ si-alors-sinon » qui représentent les décisions de gestion de la biomasse des ménages agricoles. L’étude souligne les conséquences en cascade d’un aléa pluviométrique sur le calendrier des activités agricoles, les quantités et la nature des biomasses mobilisées. Les activités les plus directement impactées sont le semis et la récolte des cultures, l’alimentation animale et, indirectement, la fertilisation des sols et la gestion des stocks alimentaires. Le modèle d’action regroupe les principales règles et modalités de gestion constituant les pratiques des ménages agricoles. Il est défini pour quatre types de ménages agriculture-élevage selon leurs activités dominantes : agricultureversusélevage et vivrierversusvente. Les ménages vivriers et élevage sont plus sensibles aux variations pluviométriques. Ils présentent une gestion plus adaptative car ils sont davantage dépendants de leur propre production. Ce modèle d’action a été conçu en vue de son intégration dans un modèle à base d’agents pour simuler les conséquences de l’aléa pluviométrique sur les flux de biomasses résultant des interactions entre les ménages agricoles d’une communauté villageoise en Afrique de l’Ouest.

The allyl phosphoester group is shown to be a protecting group for the synthesis of anionic polyphosphodiesters. Our strategy relies on the synthesis of a cyclic phosphate monomer bearing a pendant allyl phosphoester group, its easy purification by fractional distillation, its organocatalyzed ring-opening polymerization by 1,8-diazobicyclo[5.4.0]undec-7-ene (DBU) and 1-[3,5-bis(trifluoromethyl)phenyl]-3-cyclohexyl-thiourea (TU). Finally, the deprotection of the allyl phosphoester group is carried out by reaction with sodium benzenethiolate in the absence of any detectable degradation. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2642–2648

Poly(ethylene oxide) (PEO)-b-polyphosphate copolymers made of hydrophilic PEO and hydrophobic polyphosphates are amphiphilic copolymers prone to self-assemble in water into nanoparticles. In this work, nanoparticles are obtained by the self-assembly of PEO-b-polyphosphate copolymers in water in the absence of any organic co-solvent whatever the length of the pendant alkyl chain (between 4 and 7 carbon atoms) of the polyphosphate block. Remarkably, this solvent-free process remains efficient even for the most hydrophobic polyphosphate blocks. The critical aggregation concentration (CAC) of the block copolymers was determined by pyrene probe fluorescence. Finally, the efficiency of these copolymer surfactants to decrease the air-water interface was measured by air-bubble tensiometry.

International audience; Enteric methane is one of the main sources of Green House Gaz produced by ruminant livestock. Traditional pastoral systems use local natural grassland resources for livestock feeding, including a wide diversity of ligneous forages browsed by ruminants in West Africa. However few studies assessed the methane emissions of such forages. This study analyzed a large collection of ligneous and herbaceous forages, looking for estimating their methanogenic potential by using their biochemical composition predicted by NIRS and two models available in the literature (Sauvant et al. 2011, Jayanegara et al. 2012). Results showed a higher CH4 production in ligneous forages and tropical grasses when compared to tempered grasses (+10.3 vs+7.0 % respectively). However, ligneous forages contain some tannins at higher concentrations, which according to the models would tend to decrease the methanogenic potential (-16.8% and -2.3%), thus nuancing the first methane emissions results.; Le méthane entérique, représente une source importante de Gaz à effet de serre générés par l’élevage. En Afrique de l’Ouest les systèmes pastoraux traditionnels utilisent essentiellement les ressources herbacées naturelles, et périodiquement les fourrages ligneux, pour lesquels les niveaux d’émissions de méthane sont peu connus. Dans une approche prospective l’étude capitalise une importante base de données de fourrages ligneux et herbacés, dont la composition chimique a été prédite par SPIR et le potentiel méthanogène calculé selon les modèles de Sauvant et al. (2011) et Jayanegara et al.( 2012). Les résultats révèlent que les fourrages ligneux et les graminées tropicales ont tendances à émettre en moyenne plus de CH4, que les graminées tempérées (+ 10.3 et + 7.0 %). Toutefois lorsqu’elle est prise en compte leur teneur en tanins contribuerait à réduire la production potentielle de CH4 (16.8% et 2.3 %respectivement) nuançant les émissions potentielles de méthane.

La mobilité des systèmes d’élevage ovins utilisateurs d’une grande variété de ressources pâturées en Provence : impacts sur le bilan énergétique et les émissions de méthane. Réseau prairies – Symposium 2017