H2 as a fuel for flavin- and H2O2-dependent biocatalytic reactions

The soluble hydrogenase from Ralstonia eutropha provides an atom efficient regeneration system for reduced flavin cofactors using H2 as an electron source. We demonstrated this system for highly selective ene-reductase-catalyzed C[double bond, length as m-dash]C-double bond reductions and monooxygenase-catalyzed epoxidation. Reactions were expanded to aerobic conditions to supply H2O2 for peroxygenase-catalyzed hydroxylations.DFG, 284111627, H2-basierende Kaskaden für die Biosynthese von N-HeterocyclenDFG, 405325648, ,Engineering von O2-toleranten Hydrogenasen und ihre physiologischen Auswirkungen in rekombinanten Bakterien im Hinblick auf die Hydrogenase-abhängige NAD(P)H-Regeneration und H2-ProduktionDFG, 390540038, EXC 2008: UniSysCatTU Berlin, Open-Access-Mittel - 202

Infinite-contrast periodic composites with strongly nonlinear behavior: Effective-medium theory versus full-field simulations

This paper presents a combined numerical-theoretical study of the macroscopic behavior and local field distributions in a special class of two-dimensional periodic composites with viscoplastic phases. The emphasis is on strongly nonlinear materials containing pores or rigid inclusions. Full-field numerical simulations are carried out using a Fast-Fourier Transform algorithm [H. Moulinec, P. Suquet, C. R. Acad. Sci. Paris II 318, 1417 (1994)] Moulinec, P. Suquet, C. R. Acad. Sci. Paris II 318, 1417 (1994), while the theoretical results are obtained by means of the `second-order' nonlinear homogenization method [P. Ponte Castaneda, J. Mech. Phys. Solids 50, 737 (2002)]. The effect of nonlinearity and inclusion concentration is investigated in the context of power-law (with strain-rate sensitivity m) behavior for the matrix phase under in-plane shear loadings. Overall, the `second-order' estimates are found to be in good agreement with the numerical simulations, with the best agreement for the rigidly reinforced materials. For the porous systems, as the nonlinearity increases (m decreases), the strain field is found to localize along shear bands passing through the voids (the strain fluctuations becoming unbounded) and the effective stress exhibits a singular behavior in the dilute limit. More specifically, for small porosities and fixed nonlinearity m>0, the effective stress decreases linearly with increasing porosity. However, for ideally plastic behavior (m = 0), the dependence on porosity becomes non-analytic. On the other hand, for rigidly-reinforced composites, the strain field adopts a tile pattern with bounded strain fluctuations, and no singular behavior is observed (to leading order) in the dilute limit.Comment: 28 pages, 28 B&W figures, 2 tables of color maps, to be published in International Journal of Solids and Structures (in press

Co-Designing an organic framework: the ”REF’AB” Project in France

To help the development of Organic Food and Farming (OFF) systems, there is the need to consolidate conversions to OF, to support entry into organic farming, and to develop existing organic farms. Therefore a group of extensionists, researchers and educators has being working 2 years long to co-design a framework for OFF, taking into account the need to (i) embrace all forms of OFF, and at the same time to (ii) address the specificities of OFF. This project, called REF’AB (REFerentiel de l’Agriculture Biologique, 2010-2012) aims at designing the organization of set of references produced on shared methodological bases. The approach consisted in identifying key-issues of OFF systems, defining indicators, identifying relevant databases and references to feed the framework, and providing recommendations for governance to optimise the establishment and circulation of references. The outcomes of this project is that first it was not necessarily clear what a framework for OFF should be, and therefore a conference of consensus was used as a methodological tool to share views by multi-stakeholders. Second, we used sustainability assessment as an integrative process of the three levels (technical-economic, environmental, and social) and third, to manage to share a more transversal approach, we proposed a framework with 3 levels of key-proprieties: 1) security and efficiency, 2) durability through the protection of resources, and 3) autonomy and resilience

Optical and Radio Properties of Extragalactic Sources Observed by the FIRST and SDSS Surveys

We discuss the optical and radio properties of 30,000 FIRST sources positionally associated with an SDSS source in 1230 deg$^2$ of sky. The majority (83%) of the FIRST sources identified with an SDSS source brighter than r=21 are optically resolved. We estimate an upper limit of 5% for the fraction of quasars with broad-band optical colors indistinguishable from those of stars. The distribution of quasars in the radio flux -- optical flux plane supports the existence of the "quasar radio-dichotomy"; 8% of all quasars with i<18.5 are radio-loud and this fraction seems independent of redshift and optical luminosity. The radio-loud quasars have a redder median color by 0.08 mag, and a 3 times larger fraction of objects with red colors. FIRST galaxies represent 5% of all SDSS galaxies with r<17.5, and 1% for r<20, and are dominated by red galaxies. Magnitude and redshift limited samples show that radio galaxies have a different optical luminosity distribution than non-radio galaxies selected by the same criteria; when galaxies are further separated by their colors, this result remains valid for both blue and red galaxies. The distributions of radio-to-optical flux ratio are similar for blue and red galaxies in redshift-limited samples; this similarity implies that the difference in their luminosity functions, and resulting selection effects, are the dominant cause for the preponderance of red radio galaxies in flux-limited samples. We confirm that the AGN-to-starburst galaxy number ratio increases with radio flux, and find that radio emission from AGNs is more concentrated than radio emission from starburst galaxies (abridged).Comment: submitted to AJ, color gif figures, PS figures available from [email protected]

The estimation of black-hole masses in distant radio galaxies

We have estimated the masses of the central supermassive black holes of 2442 radio galaxies froma catalog compiled using data from the NED, SDSS, and CATS databases. Mass estimates based on optical photometry and radio data are compared. Relationships between the mass of the central black hole $M_p^{bh}$ and the redshift $z_p$ are constructed for both wavelength ranges. The distribution of the galaxies in these diagrams and systematic effects influencing estimation of the black-hole parameters are discussed. Upperenvelope cubic regression fits are obtained using the maximum estimates of the black-hole masses. The optical and radio upper envelopes show similar behavior, and have very similar peaks in position, $z_p \simeq 1.9$, and amplitude, $\log M_p^{bh}$ = 9.4. This is consistent with a model in which the growth of the supermassive black holes is self-regulating, with this redshift corresponding to the epoch when the accretion-flow phase begins to end and the nuclear activity falls off.Comment: 8 pages, 6 figure

Unassisted solar lignin valorisation using a compartmented photo-electro-biochemical cell

Lignin is a major component of lignocellulosic biomass. Although it is highly recalcitrant to break down, it is a very abundant natural source of valuable aromatic carbons. Thus, the effective valorisation of lignin is crucial for realising a sustainable biorefinery chain. Here, we report a compartmented photo-electro-biochemical system for unassisted, selective, and stable lignin valorisation, in which a TiO2 photocatalyst, an atomically dispersed Co-based electrocatalyst, and a biocatalyst (lignin peroxidase isozyme H8, horseradish peroxidase) are integrated, such that each system is separated using Nafion and cellulose membranes. This cell design enables lignin valorisation upon irradiation with sunlight without the need for any additional bias or sacrificial agent and allows the protection of the biocatalyst from enzymedamaging elements, such as reactive radicals, gas bubbles, and light. The photo-electrobiochemical system is able to catalyse lignin depolymerisation with a 98.7% selectivity and polymerisation with a 73.3% yield using coniferyl alcohol, a lignin monomer

Diagnostic yield of next-generation sequencing in very early-onset inflammatory bowel diseases: a multicenter study (vol 12, pg 1104, 2021)

Transplantation and immunomodulatio