Bodensystematik und Bodenklassifikation Teil I: Grundbegriffe     

Christoph Albrecht  Reinhold Jahn  Bernd Huwe 《植物养料与土壤学杂志》2005,168(1):7-20

Soil systematics and classification systems Part I: Fundamentals Soil‐ordering systems are primarily based and developed on one of two underlying principles: They are either categorized according to soil‐forming processes, or the formation of categories develops by chosen parameters. This perspective has already been established in the literature, though it is often confusing as many terms are defined and applied differently. In this contribution, the various definitions of systematics, classification, taxonomy, and identification will be clearly differentiated and summarized. The core of our work is to clearly define and contrast three terms: systematics, classification, and identification. Systematics is the fundamental scientific and deductive ordering of objects into systematic units. The purpose of this approach is to organize the entire spectrum of knowledge within a discipline into a transparent and manageable form. Classification, in direct contrast to systematics, is goal‐oriented and an inductive ordering of objects. Thus, the ordering scheme consists of classes which are clearly parameterized. Identification is the ordering of new objects into an already existing systematics or classification system. Close attention is paid to both the differences and the similarities between a systematics and a classification system, especially pertaining to their practical applications. The identification requires that the category‐forming characteristics can be measured (e.g., for soil systematics, these are the soil‐forming processes and factors). Currently, it is unfortunately not feasible to objectively quantify most soil‐forming processes. Thus, most attempts at categorizing soils by systematics are hypothetical and highly subjective in nature. The resulting identification derived from the soil systematics approach is open to questions and contestable, since a graded measuring system does not yet exist to verify these determinations. In contrast, a soil‐classification system does allow an objective soil‐profile identification, although such systems are conceived pragmatically and designed for a practical purpose (e.g., not scientifically based on process intensities). Unfortunately, such a classification system cannot be applied as a universal scientific categorization system due to this method of conception. Both categorization approaches are required in soil science in order to satisfy both the practical and the scientific aspects of the field. However, substantial research must be done to complete and verify systematics. The only viable short‐term solution is through the development of a graded classification system where the categories of the system are directly derived from the current systematics approach. In the long run both the exact investigation and the detailed modeling of the soil‐forming processes are inevitable.  相似文献   

Multi-element analysis of an english peat bog soil     

Bernd Markert  Iain Thornton 《Water, air, and soil pollution》1990,49(1-2):113-123

Nineteen elements were quantitatively determined by atomic emission spectroscopy with inductively coupled plasma in peat profiles in Ringinglow Bog, Derbyshire, England. For the elements Ba, Ca, Cd, Co, Cr, Fe, La, Mn, Ni, Ti, and Zn an enrichment in the upper 5 cm of the peat bogs was found probably caused by anthropogenic influences. The elements Al, Be, Cu, and Pb showed a different distribution pattern with maximum concentration in the 5 to 15 cm layer. The elements Mg, Na, and Sr showed no enrichment in the upper 55 cm of the peat reflecting the constant input of these elements from the sea during the last few centuries. Upper parts (leaves and stems) of the plants investigated (Calluna vulgaris and Eriophorum vaginatum) only represent higher values of Pb compared with the normal element content in other plants. Compared with the results of peat profiles in a Norwegian bog, the concentrations of the comparable elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) are much higher in the English peat. Ringinglow Bog seem to be very suitable for further investigations within the scope of a global monitoring programme.  相似文献   

A conceptual framework for damage compensation schemes     

Kathleen Schwerdtner  Bernd Gruber 《Biological conservation》2007,134(3):354-360

Damage compensation schemes are widely used to mitigate human-wildlife conflicts. Despite the growing relevance of such conflicts, a theoretical framework to analyze the cost-effectiveness of damage compensation schemes is still missing. The article aims to fill this gap by proposing a conceptual framework by categorizing cost categories, which can be used to compare different types of compensation schemes. To demonstrate the value of the framework, we present an example that compares ex-post compensation and compensation in advance in the European otter (Lutra lutra) in the Upper Lusatia, Germany. We find that the two types of schemes differ widely in their transaction costs. Transaction costs themselves are closely related to the temporal and spatial distribution of damages. Therefore, the choice between the two types of compensation schemes depends on the distribution of damages, which itself depends on the species under concern. Based on this, we recommend a compensation-in-advance type of damage compensation scheme for the otter in the Upper Lusatia, Germany.  相似文献   

欧洲农机市场的开发     

BerndSeherer 《农机质量与监督》2004,(5):43-45

德国机械及制造商协会(简称VDMA)是欧洲最大的行业协会之一。VDMA成立于1892年，至今已有110多年的历史。协会的支撑是三个：网络、服务和代表会员利益，它在机械及制造行业非常活跃。VDMA是一个非赢利性的协会，拥有公司会员单位3000个，协会的工作人员达460名。VDMA作为连接会员公司与政府机构之间的桥梁，是一个自愿参加的组织，并且不接受政府  相似文献   

Santorini eruption radiocarbon dated to 1627-1600 B.C     

Friedrich WL  Kromer B  Friedrich M  Heinemeier J  Pfeiffer T  Talamo S 《Science (New York, N.Y.)》2006,312(5773):548

Precise and direct dating of the Minoan eruption of Santorini (Thera) in Greece, a global Bronze Age time marker, has been made possible by the unique find of an olive tree, buried alive in life position by the tephra (pumice and ashes) on Santorini. We applied so-called radiocarbon wiggle-matching to a carbon-14 sequence of tree-ring segments to constrain the eruption date to the range 1627-1600 B.C. with 95.4% probability. Our result is in the range of previous, less precise, and less direct results of several scientific dating methods, but it is a century earlier than the date derived from traditional Egyptian chronologies.  相似文献   

BKCa-Cav channel complexes mediate rapid and localized Ca2+-activated K+ signaling     

Berkefeld H  Sailer CA  Bildl W  Rohde V  Thumfart JO  Eble S  Klugbauer N  Reisinger E  Bischofberger J  Oliver D  Knaus HG  Schulte U  Fakler B 《Science (New York, N.Y.)》2006,314(5799):615-620

Large-conductance calcium- and voltage-activated potassium channels (BKCa) are dually activated by membrane depolarization and elevation of cytosolic calcium ions (Ca2+). Under normal cellular conditions, BKCa channel activation requires Ca2+ concentrations that typically occur in close proximity to Ca2+ sources. We show that BKCa channels affinity-purified from rat brain are assembled into macromolecular complexes with the voltage-gated calcium channels Cav1.2 (L-type), Cav2.1 (P/Q-type), and Cav2.2 (N-type). Heterologously expressed BKCa-Cav complexes reconstitute a functional "Ca2+ nanodomain" where Ca2+ influx through the Cav channel activates BKCa in the physiological voltage range with submillisecond kinetics. Complex formation with distinct Cav channels enables BKCa-mediated membrane hyperpolarization that controls neuronal firing pattern and release of hormones and transmitters in the central nervous system.  相似文献   

Bactericidal properties of pradofloxacin against veterinary pathogens     

Silley P  Stephan B  Greife HA  Pridmore A 《Veterinary microbiology》2012,157(1-2):106-111

Pradofloxacin is a new veterinary 8-cyano-fluoroquinolone developed for use against bacterial infections in dogs and cats involving both aerobic and anaerobic bacteria. The minimal bactericidal concentrations have been determined against clinical isolates of Staphylococcus pseudintermedius, Staphylococcus aureus, Escherichia coli, Pasteurella multocida, Streptococcus canis, Proteus spp., Fusobacterium spp., Porphyromonas gingivalis and Prevotella species. A subset of these species was selected, and the in vitro rate of kill by pradofloxacin was determined. For 27 of the 30 tested aerobic strains the pradofloxacin MBC was within two doubling dilutions of the MIC. For the remaining strains, the MIC and MBC were within three to four doubling dilutions. Pradofloxacin also demonstrated bactericidal activity against all anaerobic strains, and the MBC was equal to the MIC for four of the strains, within 1 doubling dilution for three strains, within 2 dilutions for a further 3 strains and within 3 dilutions for the remaining five strains. As pradofloxacin concentration was increased, a faster rate of killing was observed; bactericidal effects were seen in all cases at concentrations ≤ 0.25 μg/mL. The bactericidal activity against the anaerobic strains was marked, of particular relevance was the complete absence of regrowth even at 48 h at concentrations as low as 0.125 μg/mL. In conclusion, pradofloxacin exhibits clear bactericidal activity in terms of MBC and kill kinetics against aerobic and anaerobic clinical isolates from dogs and cats at concentrations that are greatly exceeded within the systemic circulation after administration of the recommended therapeutic doses to the target animals. It is expected that such a rapid rate of kill will play a significant role in clinical efficacy. These data demonstrate the complete and rapid killing of anaerobic bacteria by a veterinary 8-cyano-fluoroquinolone.  相似文献   

An integrative approach of organic matter stabilization in temperate soils: Linking chemistry,physics, and biology   总被引：1，自引：0，他引：1  

Ingrid Kögel‐Knabner  Klemens Ekschmitt  Heinz Flessa  Georg Guggenberger  Egbert Matzner  Bernd Marschner  Margit von Lützow 《植物养料与土壤学杂志》2008,171(1):5-13

With this topical issue, we present the work of the Priority Program 1090 of the German Research Foundation (“Deutsche Forschungsgemeinschaft DFG”): “Soils as a source and sink for CO₂ – mechanisms and regulation of organic matter stabilisation in soils”. This introduction gives an overview on the sites investigated and the major research approaches, including a glossary of major terms used in the field of soil organic matter research. We point out the advantages of integration of data from a broad field of different soil‐science disciplines and the progress achieved by application and combination of new analytical methods describing the quality and turnover of soil organic matter.  相似文献   

Tree girdling increases soil N mineralisation in two spruce stands     

Bernd Zeller  Juxiu Liu  Nina Buchmann  Andreas Richter 《Soil biology & biochemistry》2008,40(5):1155-1166

Tree girdling is a common practice in forestry whenever trees are to be killed without felling. The effect of tree girdling on soil nitrogen (N) mineralisation was estimated in both an old and a young spruce forest. The dynamics of mineral N (NO₃⁻–N and NH₄⁺–N) and soil microbial biomass carbon (MBC) and N (MBN) were determined for different seasons. The in situ net N mineralisation was measured by incubating soil samples in stainless steel cylinders and the gross N mineralisation rates were measured by ¹⁵N pool dilution method. Mineral N concentrations increased significantly in the girdled plots in both old and young spruce forests and showed variations between soil horizons and between sampling times. Tree girdling significantly increased net N mineralisation in both spruce forests. Annual net N mineralisation was 64 and 39 kg N ha⁻¹ in O horizon of the girdled plots in old and young forest plots, respectively, compared to 25 and 21 kg N ha⁻¹ in the control plots. Annual N mineralisation in A horizon was similar between girdled and control plots (31 kg N ha⁻¹) in the old forest whereas in the young forest A horizon N mineralisation was about 2.5 times higher in the girdled plots. As a result, the annual carbon budget was significantly more positive in the girdled plots than in the control plots in both old and young forests. However, we found significantly higher gross N mineralisation rates in both horizons in the control plots than the girdled plots in the old forest, but no differences between the treatments in the young forest. The MBC and MBN contents only showed significant changes during the first three months of the experiment and were similar later on. They first decreased as girdling removed the root carbohydrate, amino and organic acid exudation from the C sources for microorganisms then increased two months after the treatment root dieback acted as a new source of C. Mineralising microorganisms enhanced the mineral N concentrations in girdled plots as a result of greater activity rather than larger population size.  相似文献   

Comparative evaluation of six different body regions of the dog using analog and digital radiography     

Meyer-Lindenberg A  Ebermaier C  Wolvekamp P  Tellhelm B  Meutstege FJ  Lang J  Hartung K  Fehr M  Nolte I 《Berliner und Münchener tier?rztliche Wochenschrift》2008,121(5-6):216-227

In this study the quality of digital and analog radiography in dogs was compared. For this purpose, three conventional radiographs (varying in exposure) and three digital radiographs (varying in MUSI-contrast [MUSI = MUlti Scale Image Contrast], the main post-processing parameter) of six different body regions of the dog were evaluated (thorax, abdomen, skull, femur, hip joints, elbow). The quality of the radiographs was evaluated by eight veterinary specialists familiar with radiographic images using a questionnaire based on details of each body region significant in obtaining a radiographic diagnosis. In the first part of the study the overall quality of the radiographs was evaluated. Within one region, 89.5% (43/48) chose a digital radiograph as the best image. Divided into analog and digital groups, the digital image with the highest MUSI-contrast was most often considered the best, while the analog image considered the best varied between the one with the medium and the one with the longest exposure time. In the second part of the study, each image was rated for the visibility of specific, diagnostically important details. After summarisation of the scores for each criterion, divided into analog and digital imaging, the digital images were rated considerably superior to conventional images. The results of image comparison revealed that digital radiographs showed better image detail than radiographs taken with the analog technique in all six areas of the body.  相似文献