Siderophore Production by Pathogenic Mucorales and Uptake of Deferoxamine B

Clinical reports have established that mucormycosis, mainly caused by Rhizopus spp., frequently occurs in patients treated with deferoxamine B (DFO, Desferal®) which is misappropriated by these fungi. Siderophore production by twenty mucoralean isolates was therefore investigated using a commercial iron-depleted culture medium. Siderophore production was detected for most of the isolates. Our experiments confirmed that feroxamine B (iron chelate of DFO) promoted in vitro growth of Rhizopus arrhizus. Electrophoretic analysis of somatic extracts revealed iron-regulated proteins of 60 and 32 kDa which were lacking in iron-depleted culture conditions. Using a fluorescent derivative of deferoxamine B, we showed by fluorescence microscopy the entry of the siderophore within the fungal cells, thus suggesting a shuttle mechanism encompassing the uptake of the entire siderophore-ion complex into the cell. This useful tool renders possible a better understanding of iron metabolism in Mucorales which could lead to the development of new diagnostic method or new antifungal therapy using siderophores as imaging contrast agents or active drug vectors

Some qualitative properties of the solutions of the Magnetohydrodynamic equations for nonlinear bipolar fluids

In this article we study the long-time behaviour of a system of nonlinear Partial Differential Equations (PDEs) modelling the motion of incompressible, isothermal and conducting modified bipolar fluids in presence of magnetic field. We mainly prove the existence of a global attractor denoted by \A for the nonlinear semigroup associated to the aforementioned systems of nonlinear PDEs. We also show that this nonlinear semigroup is uniformly differentiable on \A. This fact enables us to go further and prove that the attractor \A is of finite-dimensional and we give an explicit bounds for its Hausdorff and fractal dimensions.Comment: The final publication is available at Springer via http://dx.doi.org/10.1007/s10440-014-9964-

Stochastic Reaction-diffusion Equations Driven by Jump Processes

We establish the existence of weak martingale solutions to a class of second order parabolic stochastic partial differential equations. The equations are driven by multiplicative jump type noise, with a non-Lipschitz multiplicative functional. The drift in the equations contains a dissipative nonlinearity of polynomial growth.Comment: See journal reference for teh final published versio

A new frog species of the subgenus Asperomantis (Anura, Mantellidae, Gephyromantis) from the Bealanana District of northern Madagascar

A recent study on a group of rough-skinned Gephyromantis frogs from Madagascar (Anura: Mantellidae: Mantellinae) established a new subgenus, Asperomantis, with five described species and one undescribed candidate species. Based on newly collected material from the Bealanana District, we address the taxonomy of this candidate species, and reveal that it consists of two populations with low genetic and morphological divergence but considerable bioacoustic differences that are obvious to the human ear. As a result, we describe some of the specimens formerly assigned to Gephyromantis sp. Ca28 as G. angano sp. n. and assign the remaining specimens from a locality between Bealanana and Antsohihy to a new Unconfirmed Candidate Species, G. sp. Ca29. Gephyromantis angano sp. n. is a small species that strongly resembles G. asper and G. ceratophrys, but it differs from these and all other Gephyromantis species by a unique, clinking advertisement call. The new species may be highly threatened by habitat fragmentation, but at present we recommend it be treated as Data Deficient until more data are available to assess its distribution. We discuss the curious relationship between G. angano sp. n. and G. sp. Ca29, which we suspect may represent a case of incipient speciation. We also identify two additional new Unconfirmed Candidate Species of Gephyromantis based on sequence data from other specimens collected during our surveys in the Bealanana District

Direct overlapping effect of f orbitals for valence fluctuating materials in Kondo regime

75.20.Hr Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions, 75.30.Mb Valence fluctuation, Kondo lattice, and heavy-fermion phenomena, 71.28.+d Narrow-band systems; intermediate-valence solids,

A tunable bandpass BAW-filter architecture using negative capacitance cicuitry.

International audienc

Frugivores and the evolution of fruit colour

The study used a comparative community approach, and tested whether distributions of fruit colours are consistent with the hypothesis that colour is an evolved signal to seed dispersers. The contrast between ripe fruits and leaf backgrounds are compared at two sites, one in Madagascar where seed dispersers are primarily night-active (red–green colour-blind lemurs), and the other in Uganda, where most vertebrate seed dispersers are day-active primates and birds with greater capacity for colour vision. Results indicate that fruit colour has evolved to contrast against background leaves in response to the visual capabilities of local seed disperser communities.German Science Foundation grant (NE 2156/1-1)NSERC CanadaThe CRC progra