The effect of soil flooding on the transformation of Fe oxides and the adsorption/desorption behavior of phosphate

As repeatedly reported, soil flooding improves the availability of P to rice. This is in contrast with an increased P sorption in paddy soils. The effects of soil flooding on the transformation of Fe oxides and the adsorption/desorption of P of two paddy soils of Zhejiang Province in Southeast‐China were studied in anaerobic incubation experiments (submerging with water in N₂ atmosphere). Soil flooding significantly increased oxalate‐extractable Fe (Fe_ox), mainly at the expense of dithionite‐soluble Fe (Fe_DCB), as well as oxalate‐extractable P (P_ox), but decreased the ratio of P_ox/Fe_ox. Flooding largely increased both, P adsorption and the maximum P adsorption capacity. The majority of newly sorbed P in the soils was P_ox, but also more newly retained P was found to be not extractable by oxalate. Flooding also changed the characteristics of P desorption in the soils. Due to a decrease of the saturation index of the P sorption capacity, P adsorbed by flooded soils was much less desorbable than that from non‐flooded soils. There are obviously significant differences in the nature of both, the Fe_ox and P_ox fractions under non‐flooded and flooded conditions. The degree of the changes in Fe_ox, P_ox, P adsorption and P desorption by flooding depended on the contents of amorphous and total Fe oxides in non‐flooded soils. Our results confirm that the adsorption and desorption behavior of P in paddy soils is largely controlled by the transformation of the Fe oxides. The reasons of the often‐reported improved P availability to rice induced by flooding, in spite of the unfavorable effect on P desorbability, are discussed.     

Influence of storage practices on acrylamide formation during potato frying

A number of parameters linked to storage of potatoes were evaluated with regard to their potential to influence the acrylamide formation in French fries. Acrylamide, which is a potential human carcinogen, is reported to be formed during the frying of potatoes as a result of the reactions between asparagine and reducing sugars. This study was conducted using three potato varieties (Bintje, Ramos, and Saturna) typically used in Belgium, The Netherlands, and the northern part of France for French fry and crisp production. Saturna, mainly used in crisp production, appeared to be the least susceptible for acrylamide formation during frying. Especially storage at low temperatures (4 degrees C) compared to storage at 8 degrees C seemed to enhance acrylamide formation due to a strong increase in reducing sugars caused by low-temperature storage. Because of the reversible nature of this physiological reaction, it was possible to achieve a significant reduction of the reducing sugars after a reconditioning of the cold-stored potatoes for 3 weeks at 15 degrees C. All changes in acrylamide concentrations could mainly be explained by the reducing sugar content of the potato (R2 = 0.84, n = 160). This means that, by ensuring a low reducing sugar content of the potato tuber, the risk for acrylamide formation will largely be reduced. Finally the use of a sprout inhibitor did not influence the composition of the potato, and thus acrylamide formation was not susceptible to this treatment.     

Predictions of soil water and crop growth dynamics using the agroecosystem models THESEUS and OPUS

The agroecosystem models THESEUS and OPUS were tested with data obtained from three agricultural experimental field plots on sandy soils without groundwater located at the moraine landscape in East Brandenburg, Germany. At each of these plots, a separate agricultural management practice was applied. Measurements of soil water contents, pressure heads, above‐ground crop biomass, and crop yield from these three plots were compared with the corresponding simulation results of both models. The comparisons of simulated with measured outputs were analyzed using the modeling‐efficiency index IA. According to these analyses, both models simulated adequately the time courses of volumetric soil water contents and above‐ground crop biomass, but the time courses of pressure heads were predicted with a lower quality by both models. As for the pressure heads, the yields simulated with both models showed greater discrepancies in comparison with the observed ones. This indicates the need of a site‐specific parameter calibration of the crop‐growth modules, especially for that included in OPUS .     

Sheep medicine,Quo Vadis?

Extract

In Europe, during the 18th century, the farm animal population was seriously reduced by the spread of disease due to increased travel and wars between states. At that time, there were no specialists in animal health, but this need was soon met by the founding of veterinary schools in France, Germany and England.     

Characterization of symptoms of senescence and chilling injury on inflorescences of Heliconia bihai (L.) cv. Lobster Claw and cv. Halloween

Inadequate temperatures during the shipping and commercialization of cut tropical flowers may accelerate the senescence process and cause chilling injury, leading to symptoms that have not yet been described for Heliconia bihai. The aim of the present study was to evaluate physiological responses in cut inflorescences of H. bihai cv. Lobster Claw (LC) and cv. Halloween (HW) as well as symptoms of senescence and chilling injury. For such, changes in fresh weight, bract color (L*, a* and b*), percentage of absolute integrity (PAI) of cell membranes and leakage of potassium ions (LPI) were determined. The flowering stems were evaluated at five different intervals after harvest (0, 2, 4, 6 and 8 d). A refrigerated treatment (RT) with a temperature of 6.5 °C and 85% relative humidity was compared to a control treatment (CT) at room temperature of 24 °C and 66% relative humidity. Both cultivars stored at 6.5 °C exhibited dryness of bract tissue (symptom of senescence) and dark stains that became brownish and evolved to necrosis (symptom of chilling injury). The visual quality of inflorescences decreased with time in both cultivars maintained without refrigeration. The severity of chilling injury increased with the length of storage time in both cultivars. There was a significant reduction in the fresh weight of inflorescences in both treatments (RT and CT) and both cultivars (LC and HW). Bract color changed in both cultivars at 6.5 °C. There was no change in PAI throughout the evaluation period in the inflorescences stored at room temperature, whereas those stored at 6.5 °C for 6 and 8 d had lower PAI values. The inflorescences in the control treatment underwent no change in LPI values, whereas those stored under refrigeration had increased LPI values after the sixth day of storage. The physiological responses of cut Heliconia flowers were influenced by storage period and temperature, as demonstrated by visual symptoms of chilling injury and senescence.     

Structure-activity relationships of triazinone herbicides on resistant weeds and resistant Chlamydomonas reinhardtii

Weeds resistant to the s-triazine herbicide atrazine also show resistance to the triazinone herbicide metribuzin. However, with highly lipophilic triazinones, thylakoids isolated from atrazine-resistant Amaranthus retroflexus (mutation at position Ser₂₆₄ of the photosystem II D-1 reaction centre protein) in general show a higher pI₅₀ value in photosystem II electron transport than those from the wild type (i.e. negative cross-resistance; ‘supersensitivity’). A quantitative structure–activity relationship (QSAR) can be established, wherein the lipophilicity of the compound plays a major role. In in-vivo experiments, it was found that the triazinone DRW2698 killed resistant Amaranthus retroflexus and Chenopodium album whereas the wild type was almost unaffected. Triazinones were further investigated in five different mutants of Chlamydomonas rheinhardtii (mutations in the D-1 protein at positions Ser₂₆₄, Ala₂₅₁, Leu₂₇₅, Phe₂₅₅, and Val²¹⁹). Inhibitory activity of all triazinones was generally enhanced in the Phe₂₅₅ mutant but decreased in the Val₂₁₉ mutant. In the other mutants, biological activity was decreased when position 3 of the triazinone was substituted by CH₃, OCH₃, SCH₃, NHCH₃ or N(CH₃)₂. However, negative cross-resistance was again observed when this position was occupied by free thiol. It is therefore suggested that these two groups of triazinones orient themselves differently within the herbicide binding niche of the photosystem II D-1 protein.     

ASSOCIATIONS BETWEEN ULTRASOUND AND CLINICAL FINDINGS IN 87 CATS WITH URETHRAL OBSTRUCTION

Urethral obstruction is a life‐threatening form of feline lower urinary tract disease. Ultrasonographic risk factors for reobstruction have not been previously reported. Purposes of this retrospective cross‐sectional study were to describe urinary tract ultrasound findings in cats following acute urethral obstruction and determine whether ultrasound findings were associated with reobstruction. Inclusion criteria were a physical examination and history consistent with urethral obstruction, an abdominal ultrasound including a full evaluation of the urinary system within 24 h of hospitalization, and no cystocentesis prior to ultrasound examination. Medical records for included cats were reviewed and presence of azotemia, hyperkalemia, positive urine culture, and duration of hospitalization were recorded. For medically treated cats with available outcome data, presence of reobstruction was also recorded. Ultrasound images were reviewed and urinary tract characteristics were recorded. A total of 87 cats met inclusion criteria. Common ultrasound findings for the bladder included echogenic urine sediment, bladder wall thickening, pericystic effusion, hyperechoic pericystic fat, and increased urinary echoes; and for the kidneys/ureters included pyelectasia, renomegaly, perirenal effusion, hyperechoic perirenal fat, and ureteral dilation. Six‐month postdischarge outcomes were available for 61 medically treated cats and 21 of these cats had reobstruction. No findings were associated with an increased risk of reobstruction. Ultrasonographic perirenal effusion was associated with severe hyperkalemia (P = 0.009, relative risk 5.75, 95% confidence interval [1.54–21.51]). Findings supported the use of ultrasound as an adjunct for treatment planning in cats presented with urethral obstruction but not as a method for predicting risk of reobstruction.     

Wechselwirkungen zwischen Boden-Huminstoffen und Metall-Ionen I. Isolierung und Charakterisierung der Boden-Huminstoffe

Interactions between soil humic substances and metal ions I. Isolation and characterization of the soil humic substances From two horizons of a podzol humic acids and fulvic acids were isolated by two different methods. The obtained samples were characterized by elemental analysis, the determination of the ash and moisture content, functional group analysis as well as FTIR-, ¹H-NMR-, and ¹³C-NMR-spectroscopic examinations. In spite of the different isolation methods humic and fulvic acids show great similarities. A higher oxidized state and a lower content of aromatic structural features are clearly observed in the fulvic acids in contrast to humic acids. Besides aromatic structural elements, distinct aliphatic sections were detected in the investigated samples, which showed a lower concentration in the less transformed fractions of the Ahe-horizon.     

Evaluation of the nutritional characteristics of a finger millet based complementary food

Finger millet (Eleusine coracana), kidney beans (Phaseolus vulgaris), peanuts (Arachis hypogoea), and mango (Mangifera indica) were processed separately and then combined, on the basis of their amino acid scores and energy content, into a complementary food for children of weaning age. The finger millet and kidney beans were processed by germination, autoclaving, and lactic acid fermentation. A mixture containing, on a dry matter basis, 65.2, 19.1, 8.0, and 7.7% of the processed finger millet, kidney beans, peanuts, and mango, respectively, gave a composite protein with an in vitro protein digestibility of 90.2% and an amino acid chemical score of 0.84. This mixture had an energy density of 16.3 kJ.g(-1) of dry matter and a decreased antinutrient content and showed a measurable improvement in the in vitro extractability for calcium, iron, and zinc. A 33% (w/v) pap made from a mix of the processed ingredients had an energy density of 5.4 kJ.g(-1) of pap, which is sufficient to meet the energy requirements of well-nourished children of 6-24 months of age at three servings a day and at the FAO average breast-feeding frequency.