Patterns of acid deposition to a Danish spruce forest     

N. E. v. Freiesleben  C. Ridder  L. Rasmussen 《Water, air, and soil pollution》1986,30(1-2):135-141

Bulk precipitation and bulk throughfall was collected during the period September to November 1984 in a Danish spruce forest. Samples were analyzed for all major anions and cations as well as strong and total acidity. The acid load to the forest ecosystem was estimated adding the throughfall fluxes of protons (79 eq ha^?1mo^?1), ammonium (99 eq ha^?1mo^?1) and a calculated estimate oflthe protons buffered by exchange processes in the canopy (75 eq ha^?1 mo^?1). This is still a minimum estimate but it exceeds the proton load determined by pH measurement in bulk throughfall and bulk precipitation by factors 3 and 6, respectively. Throughfall fluxes of all major cations and anions except ammonium decreased with distance from the trunk.  相似文献   

Temporal variation of mercury in vegetation     

Pat E. Rasmussen 《Water, air, and soil pollution》1995,80(1-4):1039-1042

Temporal changes in the Hg content of balsam fir needles (Abies balsamea) and white spruce needles (Picea glauca) were monitored at a control site over two growing seasons. Results indicated a significant increase in the Hg content of needles of both species over the course of a growing season and from one year to the next. The Hg content of new foliage more than doubled within each growing season, and was 5–10 ng g^?1 higher in the 1990 growing season than in the previous year. These results indicate that temporal variation is a potential source of error when mapping the spatial variation of Hg concentrations in vegetation. To minimize this source of error, field surveys should be completed as quickly as possible (i.e., within two or three weeks).  相似文献   

Nutritionally relevant parameters in low-phytate barley (hordeumvulgare L.) grain mutants     

Hatzack F  Johansen KS  Rasmussen SK 《Journal of agricultural and food chemistry》2000,48(12):6074-6080

Nutritionally relevant parameters in barley low-phytate mutant grains were analyzed in order to assess the potential value of these lines for future feeding trials. Phytate (myo-inositol 1,2,3,4,5,6-hexakisphosphate) levels in grains from A- and B-type low-phytate mutants corresponded to 25% and 66% of those of the parent line content, respectively. These relative decreases in phytate were accompanied by proportional increases of inorganic phosphate amounts. Apart from phytate, A-type grains also contained substantial quantities of myo-inositol 1,3,4,5-tetrakisphosphate. Phytate levels in straw and root material from mutants were similar to parent line controls, indicating that low-phytate mutations were grain specific. Analysis of K, Mg, Ca, and Zn revealed normal or slightly increased mineral cation levels in grains from all low-phytate lines, suggesting that mutationally impaired phytate accumulation did not affect mineral storage capacity. Other nutritionally important parameters such as starch and protein contents were similar to parent line controls. Finally, dynamic changes in the phosphorus composition during kernel development suggested that A-type mutations directly affected phytate synthesis, whereas B-type mutations seemed to act on regulation of synthesis.  相似文献   

Acid reign '95? — Conference summary statement     

H. Rodhe  P. Grennfelt  J. Wisniewski  C. Ågren  G. Bengtsson  K. Johansson  P. Kauppi  V. Kucera  L. Rasmussen  B. Rosseland  L. Schotte  G. Selldén 《Water, air, and soil pollution》1995,85(1):1-14

  相似文献   

Long‐term successful treatment of a donkey with cutaneous lupus erythematous with methotrexate     

Marion Mosca  Pia Randleff‐Rasmussen  Nadge Milhau  Pauline Panzuti  Myriam Meylan  Isabelle Desjardin  Didier Pin 《Veterinary dermatology》2020,31(4):313-e78

Cutaneous lupus erythematosus (CLE) is a rare immune‐mediated dermatitis. To the best of the authors’ knowledge it has not been described in donkeys. A 5‐year‐old male neutered donkey, living in south‐east France, was diagnosed with CLE. Clinical signs included generalized symmetrical areas of alopecia, erythema, crusting and scales. Diagnostic tests included examination of skin biopsy samples by histopathological and immunohistochemical analysis which demonstrated an interface dermatitis with CD8+ T cells. The skin condition was successfully treated initially with glucocorticoids and methotrexate; successful long‐term maintenance was associated with administration of methotrexate.  相似文献   

Rapid detection of propiconazole and tebuconazole in wood by solid phase desorption: ion mobility spectrometry     

J. S. Rasmussen  C. Felby  S. Prasad  H. Schmidt  G. A. Eiceman 《Wood Science and Technology》2011,45(2):205-214

The durability of wood is improved by wood preservatives. Due to new environmental legislation, commonly used active ingredients such as chromium and arsenate are being replaced by alternative and more environmentally friendly preservatives. However, the alternative wood preservatives are more difficult to detect in the wood. Detection of the preservatives is necessary in order to monitor millwork production for qualitative assessment of the wood preservative uptake. The aim of this study is to examine the use of solid phase desorption-ion mobility spectrometry (SPD-IMS) can be used for rapid detection of the wood preservatives propiconazole and tebuconazole in Scots pine (Pinus sylvestris). The findings proved that SPD-IMS is capable of detecting and distinguishing wood preservatives directly from treated wood shavings. SPD-IMS requires no additional sample preparation or extraction of the wood sample. The findings show that SPD-IMS is a fast and easily applied method for direct detection of propiconazole and tebuconazole in small wood samples.  相似文献   

Indole-3-butyric acid accelerates adventitious root formation and impedes shoot growth of Pinus elliottii var. elliottii?×?P. caribaea var. hondurensis cuttings     

Mark A. Hunt  Stephen J. Trueman  Amanda Rasmussen 《New Forests》2011,41(3):349-360

Many plantation tree species are cloned to achieve the growth, disease resistance and wood quality characteristics required for a successful economic venture. However, clonal propagation is limited by declines in adventitious root formation with increasing stock plant age. We examined the effects of immediate or delayed IBA application on adventitious root formation and subsequent root and shoot development of cuttings harvested from 8-year-old clonal hedge plants of Pinus elliottii var. elliottii × P. caribaea var. hondurensis. IBA applied at the time of setting accelerated root formation, elevating the percentage of cuttings with roots at 13 weeks post-setting from 45 to 78% and from 83 to 93% for a low- and a high-rooting clone, respectively. Final rooting percentages for the same treatments and clones (78 and 85%, and 88 and 100%, respectively, at 20 weeks post-setting) were not significantly affected by IBA application. IBA increased the root:shoot ratio of rooted cuttings by decreasing shoot weight compared with untreated cuttings, without affecting root weight, root length, root surface area or root volume. IBA was only effective when applied at the time of setting. A simple IBA treatment for cuttings from 8-year-old clonal hedges, by accelerating root production, has potential for reducing nursery costs and increasing the root system quality of containerised pine cuttings.  相似文献   

Low compliance with recommendations on folic acid use in relation to pregnancy: is there a need for fortification?     

Knudsen VK  Orozova-Bekkevold I  Rasmussen LB  Mikkelsen TB  Michaelsen KF  Olsen SF 《Public health nutrition》2004,7(7):843-850

OBJECTIVE: As a means to prevent neural tube defects (NTDs), women planning pregnancy in Denmark are recommended to take a dietary supplement of 400 microg folic acid daily during the periconceptional period. We examined compliance with this recommendation in a national survey. DESIGN: Cohort study on pregnant women in Denmark. SETTING: The Danish National Birth Cohort (DNBC). SUBJECTS: From November 2000 to February 2002, 22,000 pregnant women were recruited for DNBC. Use of dietary supplements was recorded at enrollment. Compliance with the recommendation was related to an information campaign that took place during the second half of 2001, and to lifestyle factors provided in a telephone interview by the end of the first trimester of pregnancy. RESULTS: An increase was seen in the proportion of women complying with the recommendation in the study period and this coincided with the information campaign events. However, even at the end of the period, only 22.3% of the women who had planned their pregnancy fully complied with the recommendation. No increase at all was seen in periconceptional folic acid use among women with unplanned pregnancies. Young age, low education and smoking were identified as factors that determined non-compliance. CONCLUSIONS: Alternative and more effective strategies are needed if the Danish population is to benefit fully from the knowledge that folic acid prevents NTDs. Future strategies should not only target vulnerable groups, such as the less educated and the young, but also women who get pregnant without planning this. The only possible way to reach the last group may be through fortification of foods with folic acid.  相似文献   

The effect of autumn ridging and inter-row subsoiling on potato tuber yield and quality on a sandy soil in Denmark     

Christian Bugge Henriksen  Jens Peter Mlgaard  Jesper Rasmussen 《Soil & Tillage Research》2007,93(2):309-315

Autumn ridging is a modified version of the ridge tillage system. Instead of setting up ridges during the growing season, they are established in autumn and left for the winter. Previous studies have documented positive effects of autumn ridging on potato yield and we hypothesized that subsoiling could enhance these effects. To determine the effect of autumn ridging and inter-row subsoiling on potato yield and quality a field experiment was conducted on sandy soil from 2001 to 2003. Autumn ridging resulted in an average total and marketable tuber yield of 25.6 and 9.2 t ha⁻¹, which was not significantly different from the average total and marketable yield of 25.6 and 8.9 t ha⁻¹ with ploughing. However, autumn ridging significantly reduced the incidence of black scurf from 2.5% to 2.2%. Inter-row subsoiling in the growing season significantly increased marketable potato tuber yield from 8.4 to 9.6 t ha⁻¹ and reduced the occurrence of malformed potatoes from 9.3% to 7.5%, irrespective of tillage treatment and irrigation level. There was no significant interaction between autumn ridging and subsoiling. The beneficial effect of subsoiling on marketable yield was driven by a 48.5% increase in the dry year of 2001. Subsoiling reduced the incidence of common scab from 7.8% to 6.9% when irrigation was reduced. It is concluded that at least three factors may modify the effects of subsoiling: Soil water status in the growing season, precipitation immediately before and after the subsoiling operation, and crop growth stage at the time of subsoiling.  相似文献   

The impact of trophy hunting on lions (Panthera leo) and other large carnivores in the Bénoué Complex, northern Cameroon     

B.M. Croes  P.J. Funston  G. Rasmussen  R. Buij  A. Saleh  P.N. Tumenta  H.H. de Iongh 《Biological conservation》2011,144(12):3064-3072

In West and Central Africa large carnivores have become increasingly rare as a consequence of rapid habitat destruction and lack of resources for protected area management. The Bénoué Complex (23,394 km²) in northern Cameroon is a regionally critical area for large mammal conservation. In the complex lions (Panthera leo), leopards (Panthera pardus) and spotted hyenas (Crocuta crocuta) are formally protected in three national parks and 28 hunting zones. Over-hunting may be having a strong additive effect precipitating declines in large carnivore numbers across the complex. We used a coarse level track index method to estimate the relative abundance of these three species both in hunting zones and national parks. The results were interpreted with respect to ungulate abundance, and hunting impact. There was no significant difference between the densities of medium to larger species of ungulates in the hunting zones and the national parks, and no difference in leopard and spotted hyena densities in the respective areas. However, lions occurred at significantly lower densities in the hunting zones, and even in the national parks occurred at significantly lower densities than prey biomass would predict.  相似文献