Structure of the ultrathin aluminum oxide film on NiAl(110)

The well-ordered aluminum oxide film formed by oxidation of the NiAl(110) surface is the most intensely studied metal surface oxide, but its structure was previously unknown. We determined the structure by extensive ab initio modeling and scanning tunneling microscopy experiments. Because the topmost aluminum atoms are pyramidally and tetrahedrally coordinated, the surface is different from all Al2O3 bulk phases. The film is a wide-gap insulator, although the overall stoichiometry of the film is not Al2O3 but Al10O13. We propose that the same building blocks can be found on the surfaces of bulk oxides, such as the reduced corundum (0001) surface.     

Spatial and spectral analysis of soil surface properties for an archaeological area in Aksum,Ethiopia, applying high and medium resolution data

The primary aim of this paper is to determine the spatial distribution of soil surface properties using high and medium resolution imagery data. Identification of these properties is important for determining environmental conditions resulting from anthropogenic influences, and for identifying land degradation processes within the study area which is an archaeologically important region situated to the north of Aksum (northern Ethiopia). Site specific field data were used to identify and verify the spatial distribution of soil surface properties such as soil colour, texture, and organic matter content obtained with IKONOS and ASTER images. As a result, distribution maps present the preliminary associations between land cover and soil characteristics as well as the location of archaeological sites. For all Aksumite cultural phases, the general pattern of ancient settlement remained the same and is similar to that of today: residential structures were built on well drained, high relief terrain.     

Changes in host chitinase isoforms in relation to wounding and colonization by Heterobasidion annosum: early and strong defense response in 33-year-old resistant Norway spruce clone

We studied the defense reactions of 33-year-old susceptible and resistant clones of Norway spruce (Picea abies (L.) Karst.) to the major root-rot fungus Heterobasidion annosum (Fr.) Bref. and determined if tissue cultures can be used as a model system for studying defense responses of mature trees at the molecular level. Quantitative PCR analysis of genomic DNA obtained from samples taken at different times along the lesion length in living bark indicated that the fungus was present in higher amounts and extended further into the host tissue in the susceptible clone than in the resistant clone. In protein extracts from the same lesion samples, there were differences in temporal and spatial changes in host chitinase isoform profiles between the resistant and susceptible clones. Host chitinase isoforms with pI values approximately 4.8, 4.4 and 3.7 increased more during the first 7 days after wounding and inoculation and extended further along the lesion length in the resistant clone than in the susceptible clone. These results suggest that the time from wounding and infection to induction of defense-related expression is shorter in the resistant clone indicating a more efficient host defense response than in the susceptible clone. Tissue cultures from the same clones were not resistant to H. annosum and showed no difference in the timing of the increase in chitinase isoforms in response to the pathogen. However, tissue cultures from both clones showed an increase in chitinase isoforms within 6 to 24 h past inoculation, indicating that increased chitinase expression in response to the pathogen is part of a general defense response common to both mature clones and tissue cultures.     

Evaluation of the forest growth model SILVA along an elevational gradient in Switzerland

The semi-empirical single-tree model SILVA 2.2 has been developed and parameterised using forest research and inventory data from Germany that range from the colline to the montane zone. The focus of the model evaluation presented in this study was to test the applicability of the model for the main Swiss forest types and at elevations ranging from the colline to the upper subalpine zone. To this end, SILVA was initialized using data from long-term forest yield research plots. The results at the end of the 30-year simulation were compared with observed data. The analysis of the results at each test site showed that there were no significant differences in model performance between forest types. However, the deviation between simulated and observed growth depended strongly on the elevational zone, i.e., on climate. As expected, the best results were found in the colline zone, for which the model had been calibrated, whereas the upper subalpine sites revealed the strongest differences. The quality of the data regarding forest structure that were available for model initialization had a strong impact on the simulation results, mainly at high-elevation zones (i.e., supalpine and upper subalpine). We conclude that SILVA 2.2 is a suitable tool to estimate the development of single trees and standing volume for a large fraction of the forests in Switzerland. However, extreme climate conditions should be avoided with the model, and the availability of detailed stand structure information is a key priority that has a strong effect on the quality of the simulation results.

A multiple disease test for field-based phenotyping of resistances to Fusarium head blight,yellow rust and stem rust in wheat

Wheat is affected by many diseases, in Germany eight fungal diseases are recorded during the cultivar registration process. For a commercially successful cultivar, therefore, at least moderate resistances to important diseases, like yellow rust (YR) and Fusarium head blight (FHB), are necessary. Additionally, in 2013 a regional stem rust (SR) epidemic occurred in Central Germany for the first time for decades. Our objective was to analyze the resistance of 36 commercially grown winter wheat cultivars to YR, FHB, and SR in three individual and one combined inoculation. Appreciable disease severities were achieved for YR and FHB at three to four locations in two years (= seven location × year combinations), for SR at one to two locations in two years (= three location × year combinations). Wheat cultivars showed a significant genotypic variation for all diseases with high heritabilities (0.90–0.95). Interaction between inoculation treatments (individual vs. combined) and wheat genotype was not significant for each of the three diseases. Accordingly, correlations between both inoculation treatments were very high (R²?=?0.95–0.99). Several cultivars showed multi-disease resistance (MDR) to YR, FHB, and SR. In conclusion, resistance ranking among genotypes was not changed when plants were challenged with all three pathogens together compared to factorial inoculations of only one of them. Substituting factorial inoculation trials by multi-pathogen inoculation makes it more efficient to select for MDR in practical breeding programs.     

The genetic and economic gains from forest tree breeding programmes in Scandinavia and Finland

Plantations of genetically improved forest trees are critical for economic sustainability in forestry. This review summarizes gains in objective traits and the resulting economic impact of tree breeding programmes in Scandinavia and Finland. Genetic improvement of forest trees in these countries began in the late 1940s, when the first phenotypically superior plus-trees were selected from natural environments. The main findings from this review are that (i) tree breeding can increase volume growth in the range 10–25%, and (ii) the bare land value associated with genetically improved trees gives a better return on investment and a shorter rotation period compared to the unimproved forests. As some Nordic countries are quite dependent on the forest industry, breeding programmes that have resulted in economic gains have been beneficial for society. Growth and wood quality traits are often adversely correlated, and the weighting of traits from an economic perspective could provide an index for determining maximum profit from breeding. Tree breeding faces an array of challenges in the future, such as changes in silviculture, climate, new pests and diseases, and demand for wood-based products.     

The prospects of silver fir (Abies alba Mill.) and Norway spruce (Picea abies (L.) Karst) in mixed mountain forests under various management strategies,climate change and high browsing pressure

European Journal of Forest Research - In the Dinaric Mountains, the future of silver fir and Norway spruce appears to be uncertain, especially given the threat of climate change to both species and...     

Use of threshold serum and milk ketone concentrations to identify risk for ketosis and endometritis in high-yielding dairy cows

OBJECTIVE: To use threshold concentrations of acetone and beta-hydroxybutyrate in milk and serum, respectively; identify risk for ketosis and endometritis; and assess analyses of blood and milk samples as predictors of risk for ketosis in high-yielding dairy cows. ANIMALS: 90 multiparous Holstein cows. PROCEDURE: At intervals before and after parturition, blood samples were obtained for determination of glucose, nonesterified fatty acids, leptin, insulin, insulin-like growth factor-1, and beta-hydroxybutyrate concentrations. Samples of milk were obtained at similar intervals after parturition for determination of fat content and concentrations of acetone, protein, and lactose. Reproductive examination of each cow was performed weekly. RESULTS: For each cow, threshold concentrations of acetone and beta-hydroxybutyrate were calculated as 75th and 90th percentiles of maximum postpartum concentrations of acetone in milk (0.40 and 0.87 mmol/L) and beta-hydroxybutyrate in serum (2.30 and 3.51 mmol/L). Significant decrease in milk production (442 to 654 kg of energy-corrected milk/305-day period per cow) was associated with acetone or beta-hydroxybutyrate in excess of threshold values. Milk acetone concentrations > 0.40 mmol/L were associated with 3.2 times higher risk for endometritis. Low plasma glucose, high serum beta-hydroxybutyrate, and high milk acetone concentrations during week 1 after parturition were indicators of increased risk for ketosis later during lactation. CONCLUSIONS AND CLINICAL RELEVANCE: Determination of milk acetone concentration during the week after parturition may identify cows at risk for ketosis and endometritis; with appropriate interventions, development of disease and production losses may be reduced.