Potential Response of Soil-Borne Fungal Pathogens Affecting Crops to a Scenario of Climate Change in Europe

A study was carried out on the potential response of soil-borne pathogens causing crop yield losses under a climate change scenario in Europe. A controlled chamber set of experiments was carried out to quantify pathogen response to temperature using pure colonies of three soil-borne fungi, representative of low (Fusarium nivale), medium-high (Athelia rolfsii) and high (Macrophomina phaseolina) temperature requirements. A generic model to simulate fungal growth response to temperature based on these experiments was developed and linked to a soil temperature model component, and to components to simulate soil water content accounting for crop water uptake of potential hosts. Pathogens relative growth was simulated over Europe using the IPCC A1B emission scenario as realization of the Hadley-CM3 global climate model, available from the European Commission and processed for use with biophysical models. The simulations resulting from using the time span centred on 2030 were compared to the baseline, centred on the year 2000, using a sample of 30 years of daily weather. The general trend of soil-borne pathogens response to the scenario of climate change is a relative increase in growth in colder areas of Europe, as a function of their temperature requirements. Projections of F. nivale in the future indicate a relative increase of this winter pathogen of wheat in Northern European countries. A. rolfsii and M. phaseolina, two soil-borne pathogens typical of warmer agricultural areas, could find more favourable conditions in areas of the Central Europe, but they differentiated in Southern Europe where A. rolfsii resulted affected by summer soil temperatures above optimum

Growth-mode investigation of epitaxial EuS on InAs(100)

A persistent challenge in the field of spintronics is the search for suitable materials that enable the circumvention of the impedance mismatch preventing efficient spin-injection from metallic ferromagnetic conductors into semiconductors. One promising material is europium sulfide (EuS), a ferromagnetic semiconductor below the Curie temperature of 16.5 K. Investigation and optimization of the conditions required for high-quality growth of epitaxial EuS films on suitable substrates are thus of particular interest for the creation of efficient devices. We present the results of a growth-mode study employing atomic force microscopy and spot-profile analysis low-energy electron diffraction (SPA-LEED) of epitaxial EuS thin films deposited by electron-beam evaporation on InAs(100) substrates with varying combinations of, respectively, growth and annealing temperatures, Tg and Ta, from room temperature to 400 °C. We observed Stranski-Krastanov-like growth featuring low-roughness surfaces with root mean square values between 0.4 – 0.9 nm for all temperature combinations. An increased tendency for nucleation into grains and islands was observed for higher Ta from 300 – 400 °C. The corresponding nucleation mode, defined by varying degrees of 2D and 3D nucleation, was dependent on Tg. A 2D island growth mode was observed for Tg = 150 °C and Ta = 400 °C featuring a sharp and bright SPA-LEED pattern. This suggests the formation of a highly ordered, smooth surface for these growth conditions thereby providing a good starting point for optimization attempts for potential future devices

Spin injection from EuS/Co multilayers into GaAs detected by polarized electroluminescence

We report on the successful spin injection from EuS/Co multilayers into (100) GaAs at low temperatures. The spin injection was verified by means of polarized electroluminescence (EL) emitted from AlGaAs/GaAs-based spin-light-emitting diodes in zero external magnetic field. Spin-polarized electrons were injected from prototype EuS/Co spin injector multilayers. The use of semiconducting and ferromagnetic EuS circumvents the impedance mismatch. The EL was measured in side emission with and without an external magnetic field. A circular polarization of 5% at 8 K and 0 T was observed. In view of the rather rough interface between the GaAs substrate and first EuS layer, improvement of the interface quality is expected to considerably enhance the injected electron spin polarization

Uncertainty quantification for mineral precipitation and dissolution in fractured porous media

In this work we present an uncertainty quantification analysis to determine the influence and importance of some physical parameters in a reactive transport model in fractured porous media. An accurate description of flow and transport in the fractures is key to obtain reliable simulations, however, fractures geometry and physical characteristics pose several challenges from both the modeling and implementation side. We adopt a mixed-dimensional approximation, where fractures and their intersections are represented as objects of lower dimension. To simplify the presentation, we consider only two chemical species: one solute, transported by water, and one precipitate attached to the solid skeleton. A global sensitivity analysis to uncertain input data is performed exploiting the Polynomial Chaos expansion along with spectral projection methods on sparse grids

The safety profile of drotrecogin alfa (activated)

Continued safety assessment is essential for any newly approved therapy. Drotrecogin alfa (activated; DrotAA), which is approved for use in severe sepsis, has undergone clinical trials with corresponding safety analyses since 1995. However, the only comprehensive review of all trials is that reported in 2003 by Bernard and coworkers. This is an important review that focuses on the safety profile of DrotAA in all published studies (six randomized clinical trials and five national registry studies) and in previously unpublished data. DrotAA treatment is associated with an increased risk for bleeding (which in general is manageable). Nevertheless, the available evidence shows that any adverse effects of DrotAA are outweighed by its benefits in patients with severe sepsis who are at high risk for death. So far, more than 9,000 patients have been enrolled in clinical trials involving DrotAA, providing a valuable safety database. It is of note that although DrotAA does increase the risk of bleeding, this has not been associated with an overall increase in the rate of all severe adverse events

Verification of antiferromagnetic exchange coupling at room temperature using polar magneto-optic Kerr effect in thin EuS/Co multilayers with perpendicular magnetic anisotropy

We report on magneto-optic Kerr measurements in polar geometry carried out on a series of thin Co/EuS multilayers on suitable Co/Pd-multilayer substrates. Thin Co/EuS multilayers of a few nanometers individual layer thickness usually have their magnetization in plane. Co/Pd multilayers introduce a perpendicular magnetic anisotropy in the Co/EuS layers deposited on top, thus making it possible to measure magneto-optic signals in the polar geometry in remanence in order to study exchange coupling. Magneto-optic Kerr-effect spectra and hysteresis loops were recorded in the visible and ultraviolet photon-energy range at room temperature. The EuS contribution to the magneto-optic signal is extracted at 4.1 eV by combining hysteresis loops measured at different photon energies with polar magneto-optic Kerr-effect spectra recorded in remanence and in an applied magnetic field of 2.2 T. The extracted EuS signal shows clear signs of antiferromagnetic coupling of the Eu magnetic moments to the Co layers. This implies that the ordering temperature of at least a fraction of the EuS layers is above room temperature proving that magneto-optic Kerr- effect spectroscopy can be used here as a quasi-element-specific method

Possibility to realize spin-orbit-induced correlated physics in iridium fluorides

Recent theoretical predictions of "unprecedented proximity" of the electronic ground state of iridium fluorides to the SU(2) symmetric $j_{\mathrm{eff}}=1/2$ limit, relevant for superconductivity in iridates, motivated us to investigate their crystal and electronic structure. To this aim, we performed high-resolution x-ray powder diffraction, Ir L$_3$-edge resonant inelastic x-ray scattering, and quantum chemical calculations on Rb$_2$[IrF$_6$] and other iridium fluorides. Our results are consistent with the Mott insulating scenario predicted by Birol and Haule [Phys. Rev. Lett. 114, 096403 (2015)], but we observe a sizable deviation of the $j_{\mathrm{eff}}=1/2$ state from the SU(2) symmetric limit. Interactions beyond the first coordination shell of iridium are negligible, hence the iridium fluorides do not show any magnetic ordering down to at least 20 K. A larger spin-orbit coupling in iridium fluorides compared to oxides is ascribed to a reduction of the degree of covalency, with consequences on the possibility to realize spin-orbit-induced strongly correlated physics in iridium fluorides