Quantitative analysis of shadow X-ray Magnetic Circular Dichroism Photo-Emission Electron Microscopy

Shadow X-ray Magnetic Circular Dichroism Photo-Emission Electron Microscopy (XMCD-PEEM) is a recent technique, in which the photon intensity in the shadow of an object lying on a surface, may be used to gather information about the three-dimensional magnetization texture inside the object. Our purpose here is to lay the basis of a quantitative analysis of this technique. We first discuss the principle and implementation of a method to simulate the contrast expected from an arbitrary micromagnetic state. Text book examples and successful comparison with experiments are then given. Instrumental settings are finally discussed, having an impact on the contrast and spatial resolution : photon energy, microscope extraction voltage and plane of focus, microscope background level, electric-field related distortion of three-dimensional objects, Fresnel diffraction or photon scattering

Transmission XMCD-PEEM imaging of an engineered vertical FEBID cobalt nanowire with a domain wall

Using focused electron-beam-induced deposition, we fabricate a vertical, platinum-coated cobalt nanowire with a controlled three-dimensional structure. The latter is engineered to feature bends along the height: these are used as pinning sites for domain walls, which are obtained at remanence after saturation of the nanostructure in a horizontally applied magnetic field. The presence of domain walls is investigated using x-ray magnetic circular dichroism (XMCD) coupled to photoemission electron microscopy (PEEM). The vertical geometry of our sample combined with the low incidence of the x-ray beam produce an extended wire shadow which we use to recover the wire''s magnetic configuration. In this transmission configuration, the whole sample volume is probed, thus circumventing the limitation of PEEM to surfaces. This article reports on the first study of magnetic nanostructures standing perpendicular to the substrate with XMCD-PEEM. The use of this technique in shadow mode enabled us to confirm the presence of a domain wall without direct imaging of the nanowire

Identification and thermochemical analysis of high-lignin feedstocks for biofuel and biochemical production

Background - Lignin is a highly abundant biopolymer synthesized by plants as a complex component of plant secondary cell walls. Efforts to utilize lignin-based bioproducts are needed. Results - Herein we identify and characterize the composition and pyrolytic deconstruction characteristics of high-lignin feedstocks. Feedstocks displaying the highest levels of lignin were identified as drupe endocarp biomass arising as agricultural waste from horticultural crops. By performing pyrolysis coupled to gas chromatography-mass spectrometry, we characterized lignin-derived deconstruction products from endocarp biomass and compared these with switchgrass. By comparing individual pyrolytic products, we document higher amounts of acetic acid, 1-hydroxy-2-propanone, acetone and furfural in switchgrass compared to endocarp tissue, which is consistent with high holocellulose relative to lignin. By contrast, greater yields of lignin-based pyrolytic products such as phenol, 2-methoxyphenol, 2-methylphenol, 2-methoxy-4-methylphenol and 4-ethyl-2-methoxyphenol arising from drupe endocarp tissue are documented. Conclusions - Differences in product yield, thermal decomposition rates and molecular species distribution among the feedstocks illustrate the potential of high-lignin endocarp feedstocks to generate valuable chemicals by thermochemical deconstruction

Production, in continuous enzymatic membrane reactor, of an anti-hypertensive hydrolysate from an industrial alfalfa white protein concentrate exhibiting ACE inhibitory and opioid activities

International audienc

SCA0PEST, a pesticide-free agroforestry cropping system: ex-ante performance evaluation

From mid 2000, in order to address global challenges, European member states’ strategies for agriculture have progressively identified and given priority to the set up of a multi-functional farm model. In France, first reflection officially started in 2007 through the Grenelle de l'Environnement initiative from which several priority themes were identified, and dedicated measures approved. Concerning agriculture, four different objectives were selected: (a) the deployment of organic farming up to 20 % of the utilized agricultural area by 2020, (b) the Ecophyto plan for a 50 % reduction of the pesticides use, (c) the enforcement of the High Nature Value (HNV) certification scheme and the certification of at least 50 % of the French farms by 2012, and (d) the energetic diagnosis of at least 100.000 farms every 5 years within the farms' energetic performances (PPE) plan. If most of the quantified objectives have not been reached by 2014, coming into force of these measures actually goes on and represents a real opportunity for research organisms to participate to both food security and socio-environmental sustainability by the design, test and deployment of new Productive and Efficient Cropping Systems (PECS). Conversely to the majority of the PECS tested within the EXPE Dephy Ecophyto program, some have been imagined to go further the sole re-conquest of water quality by reducing drastically, or even renouncing chemical pesticides. They actually target (i) the reduction of the farm carbon footprint by reducing and/or mitigating GHG emission, (ii) the improvement of local ecological connectivity by contributing to the establishment emission, (ii) the improvement of local ecological connectivity by contributing to the establishment of new biocorridors and (iii) the financial sustainability of the experimental farms. Among the forty-one EXPE projects funded in 2012 and 2013, only one is testing and monitoring a pesticide-free agroforestry cropping system: SCA0PEST. It aims to: run an experts' panel conceptualization of the SCA0PEST cropping system by considering locally the actual and future market outlets, the hosting parcel and farmhouse agrotechnical potential, and local epidemiologic pressures; to deploy and conduce in farm conditions the cropping system; assess global and thematic performances of it; and favour the disclosure of the obtained knowledge and references towards farmers, advisers and agricultural student

Pesticide-free agroforestry cropping system: re-conception and first evaluation of the global performances of the SCAOPEST

PresentationFrom mid 2000, in order to address global challenges, European member states’ strategies for agriculture have progressively identified and given priority to the set up of a multi-functional farm models. In France, to achieve both food security and socio-environmental sustainability, the design, test and deployment of new Productive and Efficient Cropping Systems (PECS) was then engaged. Therefore, those of the particular PECS targeting the re-conquest of water quality often work at reducing drastically, or even renouncing to chemical pesticides. For that, within the 2012 EXPE Dephy Ecophyto program, a 6-years SCA0PEST project (pesticide-free agroforestry cropping system) has been funded. Considering the experimental farm objectives and local sectors' potentials, SCA0PEST objectives are (i) the review of the current conventional agroforestry cropping system and its experts' opinions-based re-design by respecting principles of integrated pest & weed management, (ii) the set up of 6 over 8 of the crops of the crop rotation each year, (iii) the ex-ante and continuous economic, environmental and social assessments of its performances. Depending on raw products sale prices, energy and fertilizers costs, preliminary SCA0PEST ex-ante assessment provided limited economic prevision, as direct margin would decrease from 140 up to 250€/ha mainly due to yield losses and additional costs for seeds. Conversely, environmental performance would be improved as annual GHG emissions from the cultivated compartment fall down to 1140 kg eq.CO2/ha (48% of the reference cropping system with pesticides); additionally, when simulated, annualized carbon sequestration by trees should reach 650 kg eq.CO2/ha. Finally, inclusion of a 2-years alfalfa production within the rotation would provide a supplementary 230€/ha indirect gain when incorporated at 40% within the dairy cows ration. If this first SCA0PEST assessment points an acceptable economic balance and an improved environmental footprint, continuous assessments would have to confirm the potential of this innovative free-pesticide cropping system

The too-long anterior process and osteochondral lesion of the talus: Is there an anatomical predisposition? A case-control study on 135 feet

Introduction: The too-long anterior process (TLAP) increases mechanical stress on the hindfoot and could lead to osteochondral lesions of the talus (OLT) by localized hyper-pressure. The purpose of this study is to investigate an association between TLAP and OLT in children. Methods: This is a retrospective, multicenter, case-control study conducted between 2010 and 2020. The OLT group was compared to a control group (CoG). TLAP is characterized by a distance between the anteromedial process of the calcaneus and the navicular bone (CN) of< 5 mm. Results: Forty-three feets were included in the OLT group and 92 in the CoG. The OLT group had a lower CN distance on CT than the CoG, a median of 2.8 mm versus 3.75 mm (p = 0.002); 86% of patients (37 feet/43) in the OLT group had a CN distance of< 5 mm (OR=3.0 [1.1; 9.5], p = 0.023) compared to 67% in the CoG. Discussion: The OLT group had an increased risk of developing TLAP compared to the CoG. Level of evidence: III