Impact of climate change on the temporal and regional occurrence of Cercospora leaf spot in Lower Saxony

Journal of Plant Diseases and Protection - The effect of climate change on the temporal and regional occurrence of Cercospora leaf spot (CLS) of sugar beet in Lower Saxony is analysed using the...     

Predicting and modelling availability of fluoride in soil from sorption properties

Usage of alkaline and saline groundwater with elevated concentrations of fluoride (F⁻) for irrigation of pastures requires an assessment of the mobility of F⁻ within the plant-water-soil continuum. Factors influencing F⁻ sorption and desorption in 95 Australian soils were examined. Pronounced differences in F⁻ sorption were observed across the soils, but these differences could not be explained by differences in soil pH, electrical conductivity or organic carbon. Rather, sorption was correlated with the content of Fe/Al hydrous oxides and kaolinite in soil. Sorption of F⁻ onto soils increased the solution pH and the ratio of (F⁻ adsorbed) to (OH⁻ desorbed) was consistently below 1, thereby indicating that adsorption of F⁻ results in the release of water and hydroxyl groups from, or co-adsorption of protons to, the sorbent surface. Maximum sorption occurred at pH values of approximately 5–6, whilst sulphate slightly increased (<5%) F⁻ sorption. Desorption was slightly decreased (~3%–7%) in presence of sulphate anions. Hence, it is unlikely that irrigation of soil with alkaline and saline groundwater, in combination with soil applications of gypsum and sulphur to limit pH fluctuations, would increase mobility of F⁻ in soil. Finally, the irrigation of soil columns with 1200–1500 mm of alkaline and saline groundwater containing 0.18 mM F⁻, as would commonly occur in irrigation systems using coal seam gas associated water in Australia, resulted in a F⁻ concentration of 0.05 mM at 10 cm depth and the measured values were in excellent agreement with modelled F⁻ movement based on sorption parameters. Thus, sorption parameters can be used to identify soils which minimize movement of F⁻ because of their strong F⁻ sorption. Based on these results, safe limits for irrigation of soil can be established which avoid F⁻ toxicity risks to plants, animals and contamination of water resources.     

Pretreatment with feline interferon omega and the course of subsequent infection with feline herpesvirus in cats

OBJECTIVE: Recombinant feline interferon omega (rFeIFN-omega), a type I IFN, may have the potential to limit virus replication and associated clinical signs when administered early on in the course of feline herpesvirus type 1 (FHV-1) infection and reactivation, respectively. The effect of rFeIFN-omega pretreatment on the course of subsequent FHV-1 infection in cats was investigated. ANIMALS STUDIED: Nine SPF cats were divided into an IFN group (n = 5) and a control-group (n = 4). PROCEDURES: The IFN group was pretreated for 2 days with 10 000 units rFeIFN-omega twice a day topically into both eyes and 20 000 units rFeIFN-omega once a day orally, whereas the control group was mock-treated. Subsequently all cats were infected with FHV-1. Samples for FHV-1 DNA detection and quantitation, virus isolation, and titration of FHV-1 antibodies were collected. Clinical and ocular signs were recorded and scored. RESULTS: Courses of median individual clinical and ocular scores and virus load did not differ significantly between both groups using anova for repeated measurements. Analysis (anova) of each individual ocular parameter revealed significantly high scores for epithelial keratitis (P = 0.016) in the IFN group compared to the control group. Periods of virus shedding did not differ significantly between both groups using the Wilcoxon rank sum test. CONCLUSIONS: Results indicated a lack of beneficial effects of rFeIFN-omega pretreatment in the course of primary FHV-1 infection in cats.     

The foot and ankle of Australopithecus sediba

A well-preserved and articulated partial foot and ankle of Australopithecus sediba, including an associated complete adult distal tibia, talus, and calcaneus, have been discovered at the Malapa site, South Africa, and reported in direct association with the female paratype Malapa Hominin 2. These fossils reveal a mosaic of primitive and derived features that are distinct from those seen in other hominins. The ankle (talocrural) joint is mostly humanlike in form and inferred function, and there is some evidence for a humanlike arch and Achilles tendon. However, Au. sediba is apelike in possessing a more gracile calcaneal body and a more robust medial malleolus than expected. These observations suggest, if present models of foot function are correct, that Au. sediba may have practiced a unique form of bipedalism and some degree of arboreality. Given the combination of features in the Au. sediba foot, as well as comparisons between Au. sediba and older hominins, homoplasy is implied in the acquisition of bipedal adaptations in the hominin foot.     

Cloudwater chemistry in the subcooled droplet regime at Mount Sonnblick (3106 M A.S.L., Salzburg,Austria)

Cloudwater and wet precipitation (snow) samples were collected at Mount Sonnblick during two field campaigns in May and November 1991. A newly designed active cloud water samples was used. Concentrations of major anions, cations and carboxylic acids were determined. Cloudwater and wet precipitation samples were generally more acidic in the warm season than in the cold season. Average cloudwater pH was 4.2 in May and 4.5 in November, average pH in snow was 4.4 in May and 5.1 in November. Average levels for sulfate (May: 96 μeq L^?1, November: 64 μeq L^?1) and nitrate (May: 27 μeq L^?1, November: 32 μeq L^?1) in cloudwater at SBO (3 km altitude) were considerably lower than at high mountain sites (0.9–2 km altitude) in the Eastern U.S.A. Cold season levels of sulfate in cloud water at SBO were as low as cloud water levels observed in Alaska. Equivalent concentrations of sulfate, nitrate and ammonium in snow precipitation were basically lower or equal compared to cloudwater but showed higher concentrations and stronger acidity in both phases in May than in November. Cloud to snow ratios for major ions were higher in November showing a wider spread than in May. Average cloud to snow ratios for sulfate were 2.4 in May and 3.5 in November. For nitrate the ratio was 1.7 in May and 2.1 in November. The lower cloud to snow ratios for nitrate are explained by the ability of the ice phase to scavenge nitric acid. Cloud to snow ratios were similar to measurements from the Swiss Alps and generally equal or lower than high elevation cloud to rain ratios from the U.S.A. Cloud to snow ratios for sulfate were used to reconstruct the mixing ratio of sublimation grown ice phase and cloud water droplets during the riming process of the ice particles in the seeder-feeder mechanism. The mixing ratio of ice phase and cloud droplets was estimated to be 1.4 in May and 2.5 in November. Sulfate to nitrate ratios were higher in cloud water than in snow and within the range of values found in North America. Generally, sulfate was more concentrated than nitrate at an equivalent basis for both cloudwater and rainwater. Total equivalent concentrations of acetate were generally higher than those of formate which is in contrast to measurements at remote high elevation sites in the U.S.A.     

Direct derivation of maize plant and crop height from low-cost time-of-flight camera measurements

Background

In agriculture, information about the spatial distribution of crop height is valuable for applications such as biomass and yield estimation, or increasing field work efficiency in terms of fertilizing, applying pesticides, irrigation, etc. Established methods for capturing crop height often comprise restrictions in terms of cost and time efficiency, flexibility, and temporal and spatial resolution of measurements. Furthermore, crop height is mostly derived from a measurement of the bare terrain prior to plant growth and measurements of the crop surface when plants are growing, resulting in the need of multiple field campaigns. In our study, we examine a method to derive crop heights directly from data of a plot of full grown maize plants captured in a single field campaign. We assess continuous raster crop height models (CHMs) and individual plant heights derived from data collected with the low-cost 3D camera Microsoft^® Kinect^® for Xbox One? based on a comprehensive comparison to terrestrial laser scanning (TLS) reference data.

Results

We examine single measurements captured with the 3D camera and a combination of the single measurements, i.e. a combination of multiple perspectives. The quality of both CHMs, and individual plant heights is improved by combining the measurements. R² of CHMs derived from single measurements range from 0.48 to 0.88, combining all measurements leads to an R² of 0.89. In case of individual plant heights, an R² of 0.98 is achieved for the combined measures (with R² = 0.44 for the single measurements). The crop heights derived from the 3D camera measurements comprise an average underestimation of 0.06 m compared to TLS reference values.

Conclusion

We recommend the combination of multiple low-cost 3D camera measurements, removal of measurement artefacts, and the inclusion of correction functions to improve the quality of crop height measurements. Operating low-cost 3D cameras under field conditions on agricultural machines or on autonomous platforms can offer time and cost efficient tools for capturing the spatial distribution of crop heights directly in the field and subsequently to advance agricultural efficiency and productivity. More general, all processes which include the 3D geometry of natural objects can profit from low-cost methods producing 3D geodata.

     

Untersuchungen an Samenglobulinen von Leguminosen IV. Disk-elektrophoretischer Vergleich der Globulinfraktionen einigerVicia-Arten

Для диск-электрофоре тического сравнения глобулинов семян различных видовVida кислая буферн ая система, в которой разделение протеино в происходит при pH 3,8, оказ алась более пригодно й, чем щелочная (раз-деление при pH 9,3). При применении к ислой буферной системы особенно важно поддержание ко нстантной температу ры, так как в этих условиях с понижением темпера туры появляются преи мущественно агрегаты легумина, сильно изменяющие эл ектрофореграмму. Исследованные образ цыV. faba не обнаружили замет ной изменчивости электрофореграмм гл обулинов. Обсуждаются причины этой констатации. Сущ ественные различня наблюдались между ра зными видамиVida. Однако, только для группыVida sativa можно было установ ить четкую корреляци ю электрофореграмм глобулинов с таксоно мическим подразделе нием рода.     

Metabolite transfer via enzyme-enzyme complexes

The concentrations of enzyme sites in cells are usually higher than the concentrations of cognate intermediary metabolites. Therefore metabolic pathways or substantial segments of pathways may proceed by the direct transfer of metabolites from one enzyme site to the next by means of enzyme-enzyme complex formation. This mechanism of metabolite transfer differs from that usually assumed where dissociation and random diffusion of metabolite through the aqueous environment is responsible for the transfer to the next enzyme site. Since the direct transfer mechanism does not involve the aqueous environment, the energetics of metabolite interconversion can differ from expectations based on aqueous solution data. Evidence is summarized suggesting that metabolite is transformed and transferred with equal facility everywhere in the direct transfer pathway.