Historic Distribution and Ecology of Tall-Grass Prairie in Western Canada

Rapid settlement and agricultural development of western Canada in the late 1800s and early 1900s nearly eliminated the tall-grass prairie, and pre-empted a detailed description by ecologists. A combination of literature review and historical ecological analysis of soils, climate, and composition data are applied to estimate the historic distribution, and area occupied by tall-grass prairie in southern Manitoba and southeastern Saskatchewan, Canada. The resulting area estimate of 20,830 km2 is more than three times any previously reported value. Some confusion of terms from the first half of the 1900s, and the impact of invasive species on vegetation patterns observed in the past 50 years, likely disguised the original distribution of tall-grass prairie. Protection and conservation efforts should now cast their nets wider to seek remnant prairies beyond the Red River valley, particularly westward along the Assiniboine, Qu’Appelle, and Souris rivers. Prospects are limited for managing these small fragments in a way that emulates the former natural disturbance regime of floods, fires, and bison grazing, but conservation and restoration efforts should continue

UV Effects of Plant-Associated Pseudomonads

Concerns about dramatic changes in the Earth’s atmosphere, such as ozone depletion, make it imperative to study how microbial communities are responding to such changes that will increase UV irradiance. Ultraviolet A (UVA) and UVB irradiation on the plant pathogen, Pseudomonas syringae pv syringae (Pss), and a plant beneficial, saprophytic root-colonizer, Pseudomonas putida (Pp) impaired their survival. Stationary-phase cells of both Pss and Pp were more susceptible to fatal UV damage than logarithmic-phase cells. This observation suggests that an active metabolism is involved in responses to protect against UV. Mutants of Pss and Pp, with insertions in rpoS, catA, and sodA and B, were all more severely affected by UV than the wild-types. These findings lead us to speculate that mechanisms to protect against oxidative stress are important in cell survival against UVA/B irradiation

The Role of Cation Acidity on the Competition between Hydrogen Evolution and CO2 Reduction on Gold Electrodes

CO2 electroreduction (CO2RR) is a sustainable alternative for producing fuels and chemicals. Metal cations in the electrolyte have a strong impact on the reaction, but mainly alkali species have been studied in detail. In this work, we elucidate how multivalent cations (Li+, Cs+, Be2+, Mg2+, Ca2+, Ba2+, Al3+, Nd3+, and Ce3+) affect CO2RR and the competing hydrogen evolution by studying these reactions on polycrystalline gold at pH = 3. We observe that cations have no effect on proton reduction at low overpotentials, but at alkaline surface pH acidic cations undergo hydrolysis, generating a second proton reduction regime. The activity and onset for the water reduction reaction correlate with cation acidity, with weakly hydrated trivalent species leading to the highest activity. Acidic cations only favor CO2RR at low overpotentials and in acidic media. At high overpotentials, the activity for CO increases in the order Ca2+ < Li+ < Ba2+ < Cs+. To favor this reaction there must be an interplay between cation stabilization of the*CO2- intermediate, cation accumulation at the outer Helmholtz plane (OHP), and activity for water reduction. Ab initio molecular dynamics simulations with explicit electric field show that nonacidic cations show lower repulsion at the interface, accumulating more at the OHP, thus triggering local promoting effects. Water dissociation kinetics is increasingly promoted by strongly acidic cations (Nd3+, Al3+), in agreement with experimental evidence. Cs+, Ba2+, and Nd3+ coordinate to adsorbed CO2 steadily; thus they enable*CO2- stabilization and barrierless protonation to COOH and further reduction products

Solvent Effect on Electrochemical CO₂ Reduction Reaction on Nanostructured Copper Electrodes

The electrochemical reduction of CO2 (CO2RR) is a sustainable alternative for producing fuels and chemicals, although the production of highly desired hydrocarbons is still a challenge due to the higher overpotential requirement in combination with the competitive hydrogen evolution reaction (HER). Tailoring the electrolyte composition is a possible strategy to favor the CO2RR over the HER. In this work we studied the solvent effect on the CO2RR on a nanostructured Cu electrode in acetonitrile solvent with different amounts of water. Similar to what has been observed for aqueous media, our online gas chromatography results showed that CO2RR in acetonitrile solvent is also structure-dependent, since nanocube-covered copper (CuNC) was the only surface (in comparison to polycrystalline Cu) capable of producing a detectable amount of ethylene (10% FE), provided there is enough water present in the electrolyte (&gt;500 mM). In situ Fourier Transform Infrared (FTIR) spectroscopy showed that in acetonitrile solvent the presence of CO2 strongly inhibits HER by driving away water from the interface. CO is by far the main product of CO2RR in acetonitrile (&gt;85% Faradaic efficiency), but adsorbed CO is not detected. This suggests that in acetonitrile media CO adsorption is inhibited compared to aqueous media. Remarkably, the addition of water to acetonitrile has little quantitative and almost no qualitative effect on the activity and selectivity of the CO2RR. This indicates that water is not strongly involved in the rate-determining step of the CO2RR in acetonitrile. Only at the highest water concentrations and at the CuNC surface, the CO coverage becomes high enough that a small amount of C2+ product is formed

Scaling Law and Aging Phenomena in the Random Energy Model

We study the effect of temperature shift on aging phenomena in the Random Energy Model (REM). From calculation on the correlation function and simulation on the Zero-Field-Cooled magnetization, we find that the REM satisfies a scaling relation even if temperature is shifted. Furthermore, this scaling property naturally leads to results obtained in experiment and the droplet theory.Comment: 8 pages, 7 figures, to be submitted to J. Phys. Soc. Jp

D9.2 Report, containing internal deliverable outcomes ID9.2-ID9.11

The aim of this deliverable is to report on TENCompetence training activities from the project month 13 to 30The work on this publication has been sponsored by the TENCompetence Integrated Project that is funded by the European Commission's 6th Framework Programme, priority IST/Technology Enhanced Learning. Contract 027087 [http://www.tencompetence.org