On the Isotopic Composition of Pb in Cloud Waters in Central Germany. A Source Discrimination Study     

Haack  Udo K.  Gutsche  Frank H.  Plessow  Kirsten  Heinrichs  Hartmut 《Water, air, and soil pollution》2002,139(1-4):261-288

Fifty seven (57) cloud water samples collected in 1 hr intervals during 9cloud events in 1997 at the summit of the Brocken (altitude 1142 m) in Central Germany were analyzed for their Pb concentrations and isotopic compositions. For comparison, filterdusts of such possible emitters as power plants, cement factories, waste incinerators, cars and others were also studied.Profiles over many hours reveal changes in composition correlatedwith changes in the origin of the air masses. Five main groups ofpossible sources of the Pb can be distinguished: most importantare (1) the European standard pollution ESP dominating the continent from Germany over France to Scandinavia and (2) industrial Pb (and soot from car exhausts) followed by (3) urban waste incinerators as well as (4) perhaps ores from Norilsk/Siberia, and, somewhat uncertain, (5) ores from PaleozoicEuropean deposits. Local and daily varying anthropogenic emissions of the sources (2–5) cause scatter of the points around the ESP correlation line. In soils all these variationsand individual signatures are levelled out so that specific sources of pollution cannot be identified anymore. Geogenic Pbfrom rocks and soils is the same as that from power plants and cement factories. It is one of the two nominal end components making up the mixture of the ESP. The less radiogenic end component of this mix which must contain Pb from very old deposits is somewhat elusive: none of the large Archaic or Proterozoic deposits could be identified. Most probably numerous sources contribute to this Pb. Pb from leaded gasoline seems to be absent or is hidden under the five components dominating the composition of the Pb in the European environment. This probably reflects phasing out of such gasoline in most European countries. The Pb in the clouds may contain a small component of old Proterozoic or even Archaic Pb, but it can also be modelled with Paleozoic Pb.  相似文献   

Risks of Boron Toxicity in Canola and Lupin by Forms of Boron Application in Acid Sands of South-Western Australia     

Ross F. Brennan  Richard W. Bell  Kirsten Frost 《Journal of plant nutrition》2015,38(6):920-937

Boron (B) deficiency frequently occurs on soils that are low in organic carbon (C) (<1.0% organic C), pH (soil pH_Ca <5.0), and clay content (<5% clay). Acid sands with these soil properties are common in south-western Australia (SWA). Moreover, hot calcium chloride (CaCl₂) extractable B levels are commonly marginal in the acid sands of SWA. This study examined the effects of soluble and slow release soil-applied B fertilizer and foliar B sprays on crops most likely to respond to B fertilizer on these soils, canola (oil-seed rape, Brassica napus L.) and lupin (Lupinus angustifolius L.).

At 25 sites over three years, canola was grown with (0.34 kg ha-¹) or without B applied as borax [sodium tetraborate decahydrate (Na₂B₄O₇·10H₂O) 11% B], and this was followed by nine experiments with B rates [0, 0.55, 1.1 kg ha^?1, applied as borax or calcium borate (ulexite, NaCaB₅O₆(OH)₆·5(H₂O), 13% B] and foliar sprays (0.1% solution of solubor, 23% B) in 2000–2001. A further five sites of B rates and sources experiments were carried out with lupin in 2000–2001. Finally, foliar B sprays (5% B w/v as a phenolic complex) at flowering were tested on seven sites in farmers’ canola crops for seed yield increases. No seed yield increases to soil-applied B were found while foliar B application at flowering increased canola seed yield in only one season across seven locations. By contrast, borax fertilizer drilled with the seed at sowing decreased canola seed yield in nine of 34-farm sites, and decreased lupin yield in two of five trials. Toxicity from drilled boron fertilizer decreased yield could be explained by decreases in plant density (by 22–40%) to values lower than required for optimum seed yield. Seedling emergence was decreased by borax applied at sowing but less so by calcium borate. Foliar B spray application never reduced seed yield due to toxicity effects.

Boron fertilizer drilled with the seed increased the B concentration in plant dry matter at early to mid-flowering. Boron application decreased the oil concentration of grain of canola at four sites. The oil yield of canola was significantly decreased at seven sites.

Notwithstanding the marginal B levels on acid sands of the SWA region, care needs to be taken on use of borax fertilizer as toxicity was induced in canola and lupin; with 0.34 to 1 kg B ha^?1(3-10 kg borax ha^?1) at sowing depressing seed yield, mostly by decreasing plant density. Rather than making general recommendation for B fertilizer application based on 0.01M CaCl₂ soil extractable B, soil and plant analysis should be used to diagnose B deficiency and B fertilizer use limited to calcium borate or foliar borax rather than soil-applied borax on low B sands.  相似文献   

Color, betalain pattern, and antioxidant properties of cactus pear (Opuntia spp.) clones     

Stintzing FC  Herbach KM  Mosshammer MR  Carle R  Yi W  Sellappan S  Akoh CC  Bunch R  Felker P 《Journal of agricultural and food chemistry》2005,53(2):442-451

Total phenolics, ascorbic acid, and betalain contents of differently colored cactus pear clones (nine Opuntia ficus-indica [L.] Mill. clones and one O. robusta Wendl. clone) were investigated and related to their respective antioxidant potential assessed by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. TEAC and ORAC values were very highly correlated with each other and also with values for total phenolics, betalain contents, and ascorbic acid concentrations. Total phenolics had the greatest contribution to ORAC and TEAC values. High-performance liquid chromatography (HPLC)-diode array detector (DAD)-tandem mass spectrometry (MS/MS) measurements of cactus pear juices permitted the differentiation of the clones based on variations in pigment patterns and betalain concentrations. The red and yellow betalains were absent in lime green colored cactus fruits. The ratio and concentration of these pigments were responsible for the yellow, orange, red, and purple colors in the other clones. Progeny of purple and lime green colored parents were characterized by 12% and 88% of plants bearing lime green and purple fruit, respectively. This implies that the genes for betalain production were lacking in the lime green fruits but could be provided by a parent with a complete set of genes, that is, purple fruits. Besides known pigments typical of Cactaceae, two unexpected betalains were identified. Whereas gomphrenin I was found for the first time in tissues of cactus plants, methionine-betaxanthin has never been described before as a genuine betalain. In addition to their alleged health-promoting properties, various combinations of yellow betaxanthins and red-purple betacyanins may allow the development of new food products without using artificial colorants.  相似文献   

Determination of Sulfate,Nitrate, and Chloride in Throughfall using Ion-Exchange Resins   总被引：1，自引：0，他引：1  

Simkin  Samuel M.  Lewis  David N.  Weathers  Kathleen C.  Lovett  Gary M.  Schwarz  Kirsten 《Water, air, and soil pollution》2004,153(1-4):343-354

Throughfall, the solution that falls from the forest canopy, is an important and commonly measured flux in forest ecosystem studies. Throughfall water and chemistry are highly variable spatially, requiring large numbers of collectors to quantify it. This and the fact that the solution can be chemically unstable make throughfall sampling very labor intensive, thus we have developed a method to reduce the field labor portion of this effort. Our throughfall collection method uses compact ion exchange resin columns that need only be collected every 1–2 months. The resin columns are subsequently extracted with 1.0 M potassium iodide (KI), releasing anions back into solution, with extraction efficiencies > 94% for sulfate, nitrate, and chloride. The extracts are analyzed by ion-chromatography (IC) to determine the total microequivalents of anions per unit area of collector surface collected over the period of resin column exposure. This ion exchange resin method was originally developed for a project in which we needed to deploy over 300 throughfall collectors to quantify throughfall variability across mountainous terrain with heterogeneous vegetation.  相似文献   

The Isotopic Composition of Anthropogenic Pb in Soil Profiles of Northern Germany: Evidence for Pollutant Pb from a Continent-wide Mixing System     

Udo K. Haack  Hartmut Heinrichs  Frank H. Gutsche  Kirsten Plessow 《Water, air, and soil pollution》2003,150(1-4):113-134

Seventy-five samples of six soil profiles from forests on different substrates plus one next to a motorway were analyzed for the variation of Pb concentration and isotopic composition with depth. A substantial fraction of the anthropogenic Pb (peak concentrations between 74 and 300 ppm) is still stored in the organic top soil, and seldom penetrates deeper than 20–30 cm. In (²⁰⁸Pb/²⁰⁶Pb) vs. (²⁰⁷Pb/²⁰⁶Pb)-diagrams the Pb in the uppermost layers of the profiles plots on an excellent correlation line (R = 0.99) indicating essentially a two-component mixing system. Values for the dust on Scottish plants, Norwegian and Swiss bogs as well as for aerosols collected over the North Atlantic (data from the literature) plot on the same correlation line showing that the Pb was deposited from a continent-wide mixing system with two apparent end members: The radiogenic one is similar to geogenic Pb and could consist of contributions from certain European ore deposits and from different soil components (e.g. silicates and Fe-oxides), power plants and cement factories. The less radiogenic component must contain or consist of Pb from Proterozoic or even Archaic ore deposits. However, the sources of this Pb remain somewhat elusive. In any case, this isotopic pattern is so consistent all over Europe that the correlation line may serve as a line of reference for quasi normal or European Standard Lead Pollution (ESLP). The gasoline derived Pb in the soils is swamped by Pb of other provenances.  相似文献   

Dental disease in alpacas. Part 2: Risk factors associated with diastemata,periodontitis, occlusal pulp exposure,wear abnormalities,and malpositioned teeth     

Kirsten Proost  Bart Pardon  Elke Pollaris  Thijs Flahou  Lieven Vlaminck 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(2):1039-1046

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An agronomic, economic and behavioral analysis of N application to cotton and wheat in post-Soviet Uzbekistan     

Kirsten M. Kienzler  Nodir DjanibekovJohn P.A. Lamers 《Agricultural Systems》2011,104(5):411-418

Cotton and winter wheat play a vital role in Uzbek agriculture: the first crop is a vital component of the national export revenues, while the latter is key in achieving independence from grain imports. Due to these strategic roles in the national economy, both crops are part of the state procurement system and, hence, are subject to strict regulations imposed to ensure budget revenues and self-sufficiency. However, many factors cause the divergence of crop yields from their technically maximum levels. We analyzed those factors, which hamper achieving the optimum response to fertilizer applications. In a stepwise procedure, we (i) reviewed the technical and financial optimum yield responses of cotton and winter wheat production to fertilizer applications and (ii) analyzed the changes of fertilizer-to-product price ratios to shed light on the agronomic and economic performance of cotton and wheat in the post-Soviet agricultural system of Uzbekistan. The analysis combined data from long-term, historical yield and fertilizer responses, agronomic N-fertilizer response experiments, and socio-economic farm surveys. Quadratic yield-response functions were used to derive economic and technical optimum rates of N-fertilizer applications. Based on the parameterized function and fertilizer-to-product price ratios observed for 1996-2003, we analyzed the difference between recommended fertilization and economic optimum application rates. Results showed that under the state procurement system, Uzbek farmers may not necessarily tend to maximize the profits from their cotton and wheat production. The level of subsidies and the differential crop support by the state induce farmers to follow the official fertilizer recommendations to ensure that they fulfill the production targets even if it implies higher production costs. The present gaps between the officially recorded yields and those technically achievable given the agro-ecological conditions in Uzbekistan cannot be narrowed by only improving N-fertilizer management. It would require additional efforts to improve cotton and wheat yields.  相似文献   

Bayesian space-time analysis of Echinococcus multilocularis-infections in foxes     

Staubach C  Hoffmann L  Schmid VJ  Ziller M  Tackmann K  Conraths FJ 《Veterinary parasitology》2011,179(1-3):77-83

A total of 26,220 foxes that were hunted or found dead in Thuringia, Germany, between 1990 and 2009 were examined for infection with Echinococcus multilocularis, the causative agent of human alveolar echinococcosis, and 6853 animals were found infected. The available data on the foxes including the location (local community; district) and the date of hunting/death were analyzed using a hierarchical Bayesian space-time model. The distribution of the model parameters and their variability was estimated on the basis of the sample size, the number of cases per spatial unit and time interval, and an adjacency matrix of the municipalities using a Markov Chain Monte Carlo simulation technique to assess the spatial and temporal changes in the distribution of the parasite. The model used to evaluate the data is widely applicable and can be applied to analyse data sets with gaps and variable sample sizes per spatial and temporal unit. In the study area, the prevalence of E. multilocularis increased from 11.9% (95% confidence interval 9.9-14.0%) in 1990 to 42.0% (39.1-44.1%) in 2005. While the infection was present in foxes only in the north-western parts of Thuringia in 1990, it had spread over the entire state by 2004. These results demand increased vigilance for human alveolar echinococcosis in Thuringia.  相似文献   

Identification of a Fusobacterium necrophorum isolate that contains a new variant of the leukotoxin gene (lktA) from the hoof of a sheep with ovine footrot     

Zhou H  Meyer K  Ganter M  Hickford JG 《Veterinary microbiology》2011,149(3-4):524-525

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Effects of a constant rate infusion of detomidine on cardiovascular function, isoflurane requirements and recovery quality in horses     

Schauvliege S  Marcilla MG  Verryken K  Duchateau L  Devisscher L  Gasthuys F 《Veterinary anaesthesia and analgesia》2011,38(6):544-554

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