Saprotrophic soil fungi to improve phosphorus solubilisation and release. In vitro abilities of several species

Modern agriculture is dependent on phosphate rock (PR), which is a nonrenewable resource. Improvement of phosphorus (P) availability for crops in agricultural soils represents a key strategy to slow down the depletion of PR. The aim of this study was to identify potential P biofertilisers among saprotrophic fungal species. We tested 30 fungal strains belonging to 28 taxa (4 Zygomycota and 24 Ascomycota) and with different life strategies. The study showed that many saprotrophic fungi have the ability to mobilise P from insoluble forms according to a variety of mechanisms. Our results expand the pool of P solubilising fungal species, also suggesting a new solubilisation index and shedding light on parameters that could be basic in the selection of efficient soil P-biofertilisers fungi. Rhizopus stolonifer var. stolonifer, Aspergillus niger and Alternaria alternata were found to be the best performing strains in terms of amounts of TCP solubilisation

THE BRIGHT AND DARK SIDE OF FINANCIAL SERVICES ECOSYSTEM

In this brief contribution we focus on the co-evolution of cybercrime and cybersecurity practices in the banking and financial sector. We draw on previous studies on outlaw innovation and organizational morphing to reconstruct the parallel and mutually influenced evolution of the bright and dark side of financial services. We identify five phases from the late 90s to the post-2015 period that show the paired configuration in actors, techniques, collaborative actions, and venues in the morphing of the two opposing sides. This paper constitutes the first step towards a broader empirical analysis on the generativity of opposing forces in digital ecosystems

Une sultane indienne à Paris : Alina d’Eldir, magnétiseuse

Cet article se propose de reconstruire la vie et la pensée d’Alina d’Eldir (vers 1762-1851), prétendue princesse indienne et magnétiseuse célèbre à Paris au milieu du xixe siècle. La notoriété d’Eldir a été favorisée par son amitié avec un certain nombre d’hommes cultivés, tels que le marquis Agricol-Joseph Fortia d’Urban (1756-1843) et Jean-Baptiste-Modeste Gence (1755-1840), qui fondèrent un groupe nommé Cercle de la noble Porte de l’Élysée d’Eldir et, dès 1835, Ordre moral asiatique universel. En outre, l’article s’interroge sur l’ouverture de l’Ordre moral asiatique universel aux pratiques magnétiques exercées par sa maîtresse, présentées dans l’ouvrage La Vérité du magnétisme prouvée par des faits (1829). En analysant les comptes-rendus des guérisons magnétiques effectuées par d’Eldir, l’essai met en évidence la composition de sa clientèle, les pratiques qu’elle utilisait et les modifications que le sexe du guérisseur pouvait apporter aux relations entre magnétiseur et magnétisé.This article aims to reconstruct the life and thought of Alina d’Eldir (c. 1762-1851), an alleged Indian princess and celebrated magnetiser in Paris during the mid-nineteenth century. D’Eldir’s notoriety was fostered by her friendship with several educated men, such as the Marquis Agricol-Joseph Fortia d’Urban (1756-1843) and Jean-Baptiste-Modeste Gence (1755-1840), who founded a group named Cercle de la noble Porte de l’Élysée d’Eldir and, from 1835, Ordre moral asiatique universel. Furthermore, the article questions the opening of the Ordre moral asiatique universel to the practice of animal magnetism exercised by its mistress, presented in the book La Vérité du magnétisme prouvée par des faits (1829). By analysing the accounts of mesmeric healings performed by d’Eldir, the essay highlights the composition of her clientele, the practices she used, and the modifications that the gender of the healer could bring to the relationship between magnetiser and magnetised person

The Dps protein of Agrobacterium tumefaciens does not bind to DNA but protects it toward oxidative cleavage: x-ray crystal structure, iron binding, and hydroxyl-radical scavenging properties.

Agrobacterium tumefaciens Dps (DNA-binding proteins from starved cells), encoded by the dps gene located on the circular chromosome of this plant pathogen, was cloned, and its structural and functional properties were determined in vitro. In Escherichia coli Dps, the family prototype, the DNA binding properties are thought to be associated with the presence of the lysine-containing N-terminal tail that extends from the protein surface into the solvent. The x-ray crystal structure of A. tumefaciens Dps shows that the positively charged N-terminal tail, which is 11 amino acids shorter than in the E. coli protein, is blocked onto the protein surface. This feature accounts for the lack of interaction with DNA. The intersubunit ferroxidase center characteristic of Dps proteins is conserved and confers to the A. tumefaciens protein a ferritin-like activity that manifests itself in the capacity to oxidize and incorporate iron in the internal cavity and to release it after reduction. In turn, sequestration of Fe(II) correlates with the capacity of A. tumefaciens Dps to reduce the production of hydroxyl radicals from H2O2 through Fenton chemistry. These data demonstrate conclusively that DNA protection from oxidative damage in vitro does not require formation of a Dps-DNA complex. In vivo, the hydroxyl radical scavenging activity of A. tumefaciens Dps may be envisaged to act in concert with catalase A to counteract the toxic effect of H2O2, the major component of the plant defense system when challenged by the bacterium

On low-frequency unsteadiness in swept shock wave–boundary layer interactions

We derive a scaling law for the characteristic frequencies of wall pressure fluctuations in swept shock wave/turbulent boundary layer interactions in the presence of cylindrical symmetry, based on analysis of a direct numerical simulations database. Direct numerical simulations in large domains show evidence of spanwise rippling of the separation line, with typical wavelength proportional to separation bubble size. Pressure disturbances around the separation line are shown to be convected at a phase speed proportional to the cross-flow velocity. This information is leveraged to derive a simple model for low-frequency unsteadiness, which extends previous two-dimensional models (Piponniau et al., J. Fluid Mech., vol. 629, 2009, pp. 87–108), and which correctly predicts growth of the typical frequency with the sweep angle. Inferences regarding the typical frequencies in more general swept shock wave/turbulent boundary layer interactions are also discussed

Specialised capabilities in integrated solutions: the role of fit

Abstract: Contingency theory suggests that the selection of coherent combinations of organisational capabilities and operational environments has important performance implications. This paper builds upon this perspective to analyse the emergence of a new business model that is modifying the structure of many industries: the provision of integrated solutions. The aim of the paper is to examine the strategic decisions behind the adoption of a business model based on integrated solutions and to understand how internal firm capabilities must be modified to match the external environment. Relying on primary data from 102 European IT firms, we discuss the value of specialised capabilities, and we analyse their degree of fit with the operational environment in which they are applied. Results show that solution providers that possess specialised capabilities obtain greater benefits when they operate in homogeneous environments. Keywords: contingency theory; integrated solutions; IT sector; capabilities. Reference to this paper should be made as follows: Ceci, F

Phosphodiesterase Type 5 Inhibitors, Sport and Doping

Phosphodiesterase type 5 inhibitors (PDE5i) (e.g., sildenafil, tadalafil, vardenafil, and avanafil) are drugs commonly used to treat erectile dysfunction, pulmonary arterial hypertension, and benign prostatic hyperplasia. PDE5i are not prohibited by the World Anti-Doping Agency (WADA) but are alleged to be frequently misused by healthy athletes to improve sporting performance. In vitro and in vivo studies have reported various effects of PDE5i on cardiovascular, muscular, metabolic, and neuroendocrine systems and the potential, therefore, to enhance performance of healthy athletes during training and competition. This suggests well-controlled research studies to examine the ergogenic effects of PDE5i on performance during activities that simulate real sporting situations are warranted to determine if PDE5i should be included on the prohibited WADA list. In the meantime, there is concern that some otherwise healthy athletes will continue to misuse PDE5i to gain an unfair competitive advantage over their competitors

Reassessment of protein stability, DNA binding, and protection of Mycobacterium smegmatis Dps.

Abstract The structure and function of Mycobacterium smegmatis Dps (DNA-binding proteins from starved cells) and of the protein studied by Gupta and Chatterji (Gupta, S., and Chatterji, D. (2003) J. Biol. Chem. 278, 5235-5241), in which the C terminus that is used for binding DNA contains a histidine tag, have been characterized in parallel. The native dodecamer dissociated reversibly into dimers above pH 7.5 and below pH 6.0, with apparent pKa values of ∼7.65 and 4.75; at pH ∼4.0, dimers formed monomers. Based on structural analysis, the two dissociation steps have been attributed to breakage of the salt bridges between Glu157 and Arg99 located at the 3-fold symmetry axes and to protonation of Asp66 hydrogen-bonded to Lys36 across the dimer interface, respectively. The C-terminal tag did not affect subunit dissociation, but altered DNA binding dramatically. At neutral pH, protonation of the histidine tag promoted DNA condensation, whereas in the native C terminus, compensation of negative and positive charges led to DNA binding without condensation. This different mode of interaction with DNA has important functional consequences as indicated by the failure of the native protein to protect DNA from DNase-mediated cleavage and by the efficiency of the tagged protein in doing so as a result of DNA sequestration in the condensates. Chemical protection of DNA from oxidative damage is realized by Dps proteins in a multistep iron oxidation/uptake/mineralization process. Dimers have a decreased protection efficiency due to disruption of the dodecamer internal cavity, where iron is deposited and mineralized after oxidation at the ferroxidase center

Fungi and arsenic. Tolerance and bioaccumulation by soil saprotrophic species

Increasing arsenic environmental concentrations are raising worldwide concern for its impacts on human health and ecosystem functionality. In order to cope with arsenic contamination, bioremediation using fungi can represent an efficient, sustainable, and cost-effective technological solution. Fungi can mitigate arsenic contamination through different mechanisms including bioaccumulation. In this work, four soil saprotrophic fungi Absidia spinosa, Purpureocillium lilacinum, Metarhizium marquandii, and Cephalotrichum nanum, isolated from soils with naturally high arsenic concentrations, were tested for their ability to tolerate different sodium arsenite concentrations and accumulate As in different cultural conditions. pH medium after fungal growth was measured to study pH variation and metabolic responses. Arsenic bioaccumulation and its influence on the uptake of other elements were investigated through multi-elemental analysis using hydride generation atomic fluorescence spectrometry (HG-AFS), inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES). Considering the increasing interest in siderophore application for metal bioremediation, the production of siderophores and their affinity for both Fe and As were also evaluated. All species were able to tolerate and accumulate As in their biomass in all of the tested conditions and produced siderophores with different affinities for Fe and As. The results suggest that the tested fungi are attractive potential candidates for the bioremediation of As contaminated soil and worthy of further investigation

Iron Incorporation into Escherichia coli Dps Gives Rise to a Ferritin-like Microcrystalline Core

Abstract Escherichia coli Dps belongs to a family of bacterial stress-induced proteins to protect DNA from oxidative damage. It shares with Listeria innocua ferritin several structural features, such as the quaternary assemblage and the presence of an unusual ferroxidase center. Indeed, it was recently recognized to be able to oxidize and incorporate iron. Since ferritins are endowed with the unique capacity to direct iron deposition toward formation of a microcrystalline core, the structure of iron deposited in the E. coli Dps cavity was studied. Polarized single crystal absorption microspectrophotometry of iron-loaded Dps shows that iron ions are oriented. The spectral properties in the high spin 3d5 configuration point to a crystal form with tetrahedral symmetry where the tetrahedron center is occupied by iron ions and the vertices by oxygen. Crystals of iron-loaded Dps also show that, as in mammalian ferritins, iron does not remain bound to the site after oxidation has taken place. The kinetics of the iron reduction/release process induced by dithionite were measured in the crystal and in solution. The reaction appears to have two phases, witht of a few seconds and several minutes at neutral pH values, as in canonical ferritins. This behavior is attributed to a similar composition of the iron core