Growth response of cuttings to drought and intermittent flooding for three Salix species and implications for riverbank soil bioengineering

Willows are used as cuttings or in fascines for riverbank soil bioengineering, to control erosion with their high resprouting ability and rapid growth. However, water availability is highly variable along riverbanks both in time and space and constitutes a major stress limiting willow establishment. A species-specific understanding of willow cutting response to water stress is critical to design successful riverbank soil bioengineering projects given exclusive use of local species is often recommended. In a three-month greenhouse experiment, we investigated the effects of three soil moisture treatments (drought—soil saturation—intermittent flooding) on survival, biomass production and root growth of cuttings of three willow species used for soil bioengineering along NE American streams (Salix discolor—S. eriocephala—S. interior). Cutting survival was high for all species and treatments (>89%). Biomass production and root volume only differed between species. S. eriocephala produced the highest biomass and root volume, and S. discolor invested more in belowground than aboveground biomass. Root length responded to soil moisture differently between species. Under intermittent flooding, S. eriocephala produced shorter roots, while S. interior produced longer roots. For riverbank soil bioengineering, S. eriocephala should be favored at medium elevation and S. interior at lower elevation

Genetic Variation in LPA, Calcific Aortic Valve Stenosis in Patients Undergoing Cardiac Surgery, and Familial Risk of Aortic Valve Microcalcification.

IMPORTANCE: Genetic variants at the LPA locus are associated with both calcific aortic valve stenosis (CAVS) and coronary artery disease (CAD). Whether these variants are associated with CAVS in patients with CAD vs those without CAD is unknown. OBJECTIVE: To study the associations of LPA variants with CAVS in a cohort of patients undergoing heart surgery and LPA with CAVS in patients with CAD vs those without CAD and to determine whether first-degree relatives of patients with CAVS and high lipoprotein(a) (Lp[a]) levels showed evidence of aortic valve microcalcification. DESIGN, SETTING, AND PARTICIPANTS: This genetic association study included patients undergoing cardiac surgery from the Genome-Wide Association Study on Calcific Aortic Valve Stenosis in Quebec (QUEBEC-CAVS) study and patients with CAD, patients without CAD, and control participants from 6 genetic association studies: the UK Biobank, the European Prospective Investigation of Cancer (EPIC)-Norfolk, and Genetic Epidemiology Research on Aging (GERA) studies and 3 French cohorts. In addition, a family study included first-degree relatives of patients with CAVS. Data were collected from January 1993 to September 2018, and analysis was completed from September 2017 to September 2018. EXPOSURES: Case-control studies. MAIN OUTCOMES AND MEASURES: Presence of CAVS according to a weighted genetic risk score based on 3 common Lp(a)-raising variants and aortic valve microcalcification, defined as the mean tissue to background ratio of 1.25 or more, measured by fluorine 18-labeled sodium fluoride positron emission tomography/computed tomography. RESULTS: This study included 1009 individuals undergoing cardiac surgery and 1017 control participants in the QUEBEC-CAVS cohort; 3258 individuals with CAVS and CAD, 41 100 controls with CAD, 2069 individuals with CAVS without CAD, and 380 075 control participants without CAD in the UK Biobank, EPIC-Norfolk, and GERA studies and 3 French cohorts combined; and 33 first-degree relatives of 17 patients with CAVS and high Lp(a) levels (≥60 mg/dL) and 23 control participants with normal Lp(a) levels (<60 mg/dL). In the QUEBEC-CAVS study, each SD increase of the genetic risk score was associated with a higher risk of CAVS (odds ratio [OR], 1.35 [95% CI, 1.10-1.66]; P = .003). Each SD increase of the genetic risk score was associated with a higher risk of CAVS in patients with CAD (OR, 1.30 [95% CI, 1.20-1.42]; P < .001) and without CAD (OR, 1.33 [95% CI, 1.14-1.55]; P < .001). The percentage of individuals with a tissue to background ratio of 1.25 or more or CAVS was higher in first-degree relatives of patients with CAVS and high Lp(a) (16 of 33 [49%]) than control participants (3 of 23 [13%]; P = .006). CONCLUSIONS AND RELEVANCE: In this study, a genetically elevated Lp(a) level was associated with CAVS independently of the presence of CAD. These findings support further research on the potential usefulness of Lp(a) cascade screening in CAVS

Bacterial Colonization of Low‐Wettable Surfaces is Driven by Culture Conditions and Topography

Effect of surface low‐wettability on bacterial colonization has become a prominent subject for the development of antibacterial coatings. However, bacteria's fate on such surfaces immersed in liquid as well as causal factors is poorly understood. This question is addressed by using a range of coatings with increasing hydrophobicity, to superhydrophobic, obtained by an atmospheric plasma polymer method allowing series production. Chemistry, wettability, and topography are thoroughly described, as well as bacterial colonization by in situ live imaging up to 24 h culture time in different liquid media. In the extreme case of superhydrophobic coating, substrates are significantly less colonized in biomolecule‐poor liquids and for short‐term culture only. Complex statistical analysis demonstrates that bacterial colonization on these low‐wettable substrates is predominantly controlled by the culture conditions and only secondary by topographic coating's properties (variation in surface structuration with almost constant mean height). Wettability is less responsible for bacterial colonization reduction in these conditions, but allows the coatings to preserve colonization‐prevention properties in nutritive media when topography is masked by fouling. Even after long‐term culture in rich medium, many large places of the superhydrophobic coating are completely free of bacteria in relation to their capacity to preserve air trapping

Sur le dualisme ontologique chez Jean-Paul Sartre : essai de relecture de L'être et le néant

Ce mémoire propose une relecture de L’être et le néant. Plutôt que d’exposer l’ontologie sartrienne dans le sens d’une cassure entre les deux régions d’être que sont l’en-soi et le pour-soi, ce travail présente celle-ci dans le sens d’un rapport entre ces deux modalités. Plus féconde et plus fidèle, cette lecture permet de redécouvrir la richesse des analyses et des descriptions que contient cet ouvrage, en particulier : celles des phénomènes, de la conscience, du circuit d’ipséité et de l’être- pour-autrui

Inkjet Printing of All Aqueous Inks to Flexible Microcapacitors for High‐Energy Storage

International audienceDue to the low energy density of commercial printable dielectrics, printed capacitors occupy a significant printing area and weight in printed electronics. It has long remained challenging to develop novel dielectric materials with printability and high energy-storage density. Here, we present a novel strategy for inkjet printing of all aqueous colloidal inks to dielectric capacitors composed of carbon nanotube electrodes and polyvinylidene fluoride (PVDF)-based dielectrics. The formulated dielectric ink is composed of negatively charged PVDF latex nanoparticles complexed with cationic chitosan molecules. Beyond the isoelectric point, the PVDF@Chitosan particles demonstrate excellent printability and film-forming properties. Chitosan serves as a strong binder to improve the printed film quality yet it introduces charged species. To mitigate the transport of mobile charges, we interlayer the printed PVDF@Chitosan film with a layer of boron nitride nanosheets. This layer is perpendicular to the electric field and serves as an efficient barrier to block the transport and the avalanche of charges, eventually leading to a recoverable energy density of 15 J cm-3 at 610 MV m-1. This energy density represents the highest value among the waterborne dielectrics. It is also superior to most of the state-of-the-art dielectric materials printed from solvent-based formulations

Parametric study of a thin piezoelectric cantilever for energy harvesting applications

International audienc

Numerical and experimental investigations of piezoelectric energy harvesters

International audienceIn order to supply low consumption electronic devices, wasted mechanical energy available in ourenvironment can be converted into useful electrical energy by piezoelectric harvesters. The two commonstructures used for vibration energy harvesting are a cantilever-based unimorph or bimorph. The unimorph isconstituted of one PZT layer bonded on an elastic one, and the bimorph is made of two PZT layers separatedwith an inner elastic shim material. Further deepening the comprehension of these mechanical energyharvesters will facilitate their design. Moreover, it is commonly known that material properties ofpiezoelectric thin films differ from bulk ones [1]. This can be a significant source of error for the devicesimulation, using analytical models or finite element (FE) models. Numerical models are powerful tools andrequire an accurate set of material properties of the PZT layer. For this purpose, an original method has beenintroduced [2], requiring only the electrical impedance measurement of the PZT layer in free-free mechanicalboundary conditions: the effective values of the electrical, mechanical and piezoelectric tensors are identifiedusing successively a one-dimensional analytical model and a three-dimensional (3D) FE model of theelectrical impedance. The pursued goal is to build a 3D FE model for the design of our harvesters.Firstly, the set of electromechanical properties of the PZT layer, taking into account mechanical anddielectric losses, is identified thanks to an original method [2], based solely on the electrical impedancecharacterization in free-free boundary conditions. But since the PZT layer is bonded on the elastic shimmaterial, and the final devices are clamped at one end, the influence of the modification of the mechanicalboundary conditions has to be determined. For this purpose, a 14μm thick layer of brass has been bondedonto a 150μm thick of PZT to form a 164μm thick unimorph structure. In the same way, another PZT layerhas been added to the unimorph structure to constitute a 314μm thick bimorph structure. For each structure, anumerical study based on the FE method has been carried out. In particular, a frequency domain study hasbeen performed on a 3D FE model in clamped-free mechanical boundary conditions to calculate theelectrical response of the considered sample in the frequency range of 60Hz-145Hz. The electricalimpedance of the sample has been measured on the same frequency range using an impedance analyzer(HIOKI IM3570, Koizumi, Ueda, Nagano, Japan) and compared to the numerical results.The electrical impedance of the samples has been computed and compared with the experiment. Thediscrepancy between modelling and experimental results is less than 4% in frequency and 16% in impedancemagnitude. This demonstrates the accuracy of our model to predict the electrical behavior of piezoelectriccantilevers in clamped-free mechanical boundary conditions. The next step of this work is to model thevibrational behavior of our clamped devices and estimate their electrical output performances (generatedvoltage, current and power as a function of the resistive load) when the clamped end of the harvester issubmitted to a vibration, with the purpose of mechanical energy harvesting