Development and characterization of environmentally friendly composites from poly(butylene succinate) (PBS) and almond shell flour with different compatibilizers

[EN] This work reports the enhancement of the properties of poly (butylene succinate) (PBS) composites containing 30 wt% almond shell flour (ASF) by using different compatibilizer families: epoxy, maleic anhydride and acrylic. With regard to the epoxy compatibilizers, epoxidized linseed oil (ELO) and epoxidized soybean oil (ESBO) were used. Two maleic anhydride-derived compatibilizers, namely, maleinized linseed oil (MLO) and dodecenyl succinic anhydride (DDSA) were used. Finally, two acrylic monomers, namely methyl methacrylate (MMA) and acrylic acid (AA) were employed. Uncompatibilized and compatibilized PBS/ASF composites were characterized in terms of their mechanical properties, morphology, thermal behaviour and thermomechanical performance. The obtained results suggest that all three vegetable oil-derived compatibilizers (ELO, ESBO and MLO) give a remarkable increase in ductile properties while poor compatibilization is obtained with the acrylic monomers. These vegetable-oil derived compatibilizers could represents an interesting environmentally friendly solution to compatibilizing polyester-type polymers and their composites with lignocellulosic materials.This work was supported by the Ministry of Economy and Competitiveness (MINECO) grant numbers MAT2014-59242-C2-1-R and MAT2017-84909-C2-2-R. L. Quiles-Carrillo acknowledges Generalitat Valenciana (GV) for financial support through a FPI grant (ACIF/2016/182) and the Spanish Ministry of Education, Culture, and Sports (MECD) for his FPU grant (FPU15/03812).Liminana, P.; Garcia-Sanoguera, D.; Quiles-Carrillo, L.; Balart, R.; Montanes, N. (2018). Development and characterization of environmentally friendly composites from poly(butylene succinate) (PBS) and almond shell flour with different compatibilizers. Composites Part B Engineering. 144:153-162. https://doi.org/10.1016/j.compositesb.2018.02.031S15316214

Inner necrosis in grapevine rootstock mother plants in the Cognac area (Charentes, France)

The incidence and quantification of decline-associated inner necrosis in grapevine rootstock mother plants have rarely been studied. In an experimental vineyard planted in 1991 at Saintes (Charentes), susceptibility to esca was evaluated in eleven common rootstock varieties. Fifty vines per rootstock variety were used as mother plants producing long canes which were severely pruned every year. No foliar symptoms, typical of grapevine wood diseases, were seen in field inspections conducted in the summer of 1996, 2002, 2003 and 2006. In 2007, nine trunks per variety were randomly selected and were cross-sectioned at the point of greatest diameter. All sections revealed typical esca necrosis, central and/or sector-shaped, indicating that such necrosis is very common. Every section was photographed and the percentage of necrotic area was calculated by either visual assessment or image-analysis. No significant difference was detected between these two calculating methods. Based on the mean percent necrotic area, rootstock varieties were ranked in order of susceptibility from the least susceptible, ‘1103 Paulsen’ (33%), to the most susceptible, ‘101-14 MGT’ (71%). The percent of necrotic area was correlated significantly with i) the incidence of mortality and ii) the percentage of vine sections showing white rot, a type of necrosis indicating an advanced stage of wood deterioration. This study confirmed that necrosis in grapevine wood is not always associated with foliar symptoms, but that it is related positively with grapevine mortality. Furthermore, wood necrosis in mother-plants poses a risk of disseminating associated fungi through propagation material

Path segmentation for beginners: an overview of current methods for detecting changes in animal movement patterns

Increased availability of high-resolution movement data has led to the development of numerous methods for studying changes in animal movement behavior. Path segmentation methods provide basics for detecting movement changes and the behavioral mechanisms driving them. However, available path segmentation methods differ vastly with respect to underlying statistical assumptions and output produced. Consequently, it is currently difficult for researchers new to path segmentation to gain an overview of the different methods, and choose one that is appropriate for their data and research questions. Here, we provide an overview of different methods for segmenting movement paths according to potential changes in underlying behavior. To structure our overview, we outline three broad types of research questions that are commonly addressed through path segmentation: 1) the quantitative description of movement patterns, 2) the detection of significant change-points, and 3) the identification of underlying processes or ‘hidden states’. We discuss advantages and limitations of different approaches for addressing these research questions using path-level movement data, and present general guidelines for choosing methods based on data characteristics and questions. Our overview illustrates the large diversity of available path segmentation approaches, highlights the need for studies that compare the utility of different methods, and identifies opportunities for future developments in path-level data analysis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40462-016-0086-5) contains supplementary material, which is available to authorized users

Etude de la croissance et de la ramification de différentes formes de cyprès : Cupressus sempervirens L. (Cupressaceae)

National audienc

Endothelial gamma-glutamyltransferase contributes to the vasorelaxant effect of S-nitrosoglutathione in rat aorta

S-nitrosoglutathione (GSNO) involved in storage and transport of nitric oxide (•NO), plays an important role in vascular homeostasis. Breakdown of GSNO can be catalyzed by γ−glutamyltransferase (GGT). We investigated whether vascular GGT influences the vasorelaxant effect of GSNO in isolated rat aorta. Histochemical localization of GGT and its activity measurement were performed by using chromogenic substrates in sections and in aorta homogenates, respectively. The role of GGT in GSNO metabolism was evaluated by measuring GSNO consumption rate (absorbance decay at 334 nm), •NO release was visualized and quantified with the fluorescent probe 4,5-diaminofluorescein diacetate. The vasorelaxant effect of GSNO was assayed using isolated rat aortic rings (in the presence or absence of endothelium). In each experiment, the role of GGT was assessed using a γ-glutamyl acceptor, glycylglycine, and a non-competitive inhibitor of GGT, serine borate complex. Specific GGT activity was histochemically localized in the endothelium. Consumption of GSNO and release of free •NO decreased and increased in presence of serine borate complex and glycylglycine, respectively. In endothelium-intact aorta, half maximal effective concentration (EC50) for GSNO (3.2 ± 0.5.10-7 M) was increased in the presence of serine borate complex serine borate complex (1.6 ± 0.2.10-6 M) and decreased with glycylglycine (4.7 ± 0.9.10-8 M). In endothelium-denuded aorta, EC50 for GSNO alone increased to 2.3 ± 0.3.10-6 M, with no change in the presence of serine borate complex. These data demonstrate the important role of endothelial GGT activity in mediating the vasorelaxant effect of GSNO in rat aorta under physiological conditions. Because new therapeutics treatments based on GSNO are actually developed, this endothelium-dependent mechanism involved in the vascular effects of GSNO should be taken into account in a pharmacological perspective

In vivo and in silico evaluation of a new nitric oxide donor, S,S′-dinitrosobucillamine

Purpose In a previous work, we have synthetized a new dinitrosothiol, i.e. S,S′-dinitrosobucillamine BUC(NO)2 combining S-nitroso-N-acetylpenicillamine (SNAP) and S-nitroso-N-acetylcysteine (NACNO) in its structure. When exposed to isolated aorta, we observed a 1.5-fold increase of •NO content and a more potent vasorelaxation (1 log higher pD2) compared to NACNO and SNAP alone or combined (Dahboul et al., 2014). In the present study, we analyzed the thermodynamics and kinetics for the release of •NO through computational modeling techniques and correlated it to plasma assays. Then BUC(NO)2 was administered in vivo to rats, assuming it will induce higher and/or longer hypotensive effects than its two constitutive S-mononitrosothiols. Methods Free energies for the release of •NO entities have been computed at the density functional theory level assuming an implicit model for the aqueous environment. Degradation products of BUC(NO)2 were evaluated in vitro under heating and oxidizing conditions using HPLC coupled with tandem mass spectrometry (MS/MS). Plasma from rats were spiked with RSNO and kinetics of RSNO degradation was measured using the classical Griess-Saville method. Blood pressure was measured in awake male Wistar rats using telemetry (n = 5, each as its own control, 48 h wash-out periods between subcutaneous injections under transient isoflurane anesthesia, random order: 7 mL/kg vehicle, 3.5, 7, 14 μmol/kg SNAP, NACNO, BUC(NO)2 and an equimolar mixture of SNAP + NACNO in order to mimic the number of •NO contained in BUC(NO)2). Variations of mean (ΔMAP, reflecting arterial dilation) and pulse arterial pressures (ΔPAP, indirectly reflecting venodilation, used to determine effect duration) vs. baseline were recorded for 4 h. Results Computational modeling highlights the fact that the release of the first •NO radical in BUC(NO)2 requires a free energy which is intermediate between the values obtained for SNAP and NACNO. However, the release of the second •NO radical is significantly favored by the concerted formation of an intramolecular disulfide bond. The corresponding oxidized compound was also characterized as related substance obtained under degradation conditions. The in vitro degradation rate of BUC(NO)2 was significantly greater than for the other RSNO. For equivalent low and medium •NO-load, BUC(NO)2 produced a hypotension identical to NACNO, SNAP and the equimolar mixture of SNAP + NACNO, but its effect was greater at higher doses (-62 ± 8 and -47 ± 14 mmHg, maximum ΔMAP for BUC(NO)2 and SNAP + NACNO, respectively). Its duration of effect on PAP (-50%) lasted from 35 to 95 min, i.e. shorter than for the other RSNO (from 90 to 135 min for the mixture SNAP + NACNO). Conclusion A faster metabolism explains the abilities of BUC(NO)2 to release higher amounts of •NO and to induce larger hypotension but shorter-lasting effects than those induced by the SNAP + NACNO mixture, despite an equivalent •NO-load

Oncocercosis and its control in Equatorial Guinea: 1997-2010

BAN EK, 199