Mandibular corrective osteotomy using novel locking compression plate 3.5/4.5/5.0 mm metaphyseal plates     

Christoph S. Klaus DVM  Carsten Vogt DVM  CeqD  Prof. Christoph J. Lischer DVM  Diplomate ECVS 《Veterinary surgery : VS》2013,42(8):984-988

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Sward patterns created by patch grazing are stable over more than a decade     

Bettina Tonn  Christoph Raab  Johannes Isselstein 《Grass and Forage Science》2019,74(1):104-114

Under extensive grazing, a mosaic pattern of frequently defoliated short patches and rarely defoliated tall patches is often formed. The agronomic and ecological consequences of this patch‐grazing pattern strongly depend on its stability between successive years. We assessed patch structure and temporal stability under three intensities of cattle stocking (moderate, lenient and very lenient) in a cattle grazing experiment established in 2002. Aerial images of the whole area taken in 2005, 2010, 2013 and 2015 were classified into short and tall patches using random forest classification. These were complemented by annual sward height measurements (2007‐2017) at 10 permanent plots per paddock, which were classified into sward height classes. The mean proportion (0.72, 0.32, 0.19) and size of short patches decreased with stocking intensity, while size of tall patches increased. Inter‐annual stability depended on patch type and stocking intensity and was particularly high for the respective dominant patch type. Of the short patch area in 2015, 0.62, 0.29 and 0.30 were classified as short in all four aerial images under moderate, lenient and very lenient grazing, respectively; the corresponding proportions for tall patches were 0.10, 0.53 and 0.65. Our results imply that short and tall patches experience persistent differences in local grazing intensity over extended periods. The long‐term effects of this heterogeneity on soil properties and vegetation composition need to be monitored to assess agronomic sustainability and ecological potential of patch‐grazed pastures.  相似文献   

Nitrogen retention and plant uptake on a highly weathered central Amazonian Ferralsol amended with compost and charcoal     

Christoph Steiner  Bruno Glaser  Wenceslau Geraldes Teixeira  Johannes Lehmann  Winfried E.H. Blum  Wolfgang Zech 《植物养料与土壤学杂志》2008,171(6):893-899

Leaching losses of N are a major limitation of crop production on permeable soils and under heavy rainfalls as in the humid tropics. We established a field trial in the central Amazon (near Manaus, Brazil) in order to study the influence of charcoal and compost on the retention of N. Fifteen months after organic‐matter admixing (0–0.1 m soil depth), we added ¹⁵N‐labeled (NH₄)₂SO₄ (27.5 kg N ha^–1 at 10 atom% excess). The tracer was measured in top soil (0–0.1 m) and plant samples taken at two successive sorghum (Sorghum bicolor L. Moench) harvests. The N recovery in biomass was significantly higher when the soil contained compost (14.7% of applied N) in comparison to only mineral‐fertilized plots (5.7%) due to significantly higher crop production during the first growth period. After the second harvest, the retention in soil was significantly higher in the charcoal‐amended plots (15.6%) in comparison to only mineral‐fertilized plots (9.7%) due to higher retention in soil. The total N recovery in soil, crop residues, and grains was significantly (p < 0.05) higher on compost (16.5%), charcoal (18.1%), and charcoal‐plus‐compost treatments (17.4%) in comparison to only mineral‐fertilized plots (10.9%). Organic amendments increased the retention of applied fertilizer N. One process in this retention was found to be the recycling of N taken up by the crop. The relevance of immobilization, reduced N leaching, and gaseous losses as well as other potential processes for increasing N retention should be unraveled in future studies.  相似文献   

Charcoal and smoke extract stimulate the soil microbial community in a highly weathered xanthic Ferralsol   总被引：2，自引：0，他引：2  

Christoph Steiner  Keshav C. Das  Marcos Garcia  Bernhard Frster  Wolfgang Zech 《Pedobiologia》2008,51(5-6):359-366

The influence of charcoal and smoke condensates (pyroligneous acid, PA) on microbial activity in a highly weathered Amazonian upland soil was assessed via measurements of basal respiration (BR), substrate-induced respiration (SIR), and exponential population increase after substrate addition. PA extracts are commonly used for fertilizer or as pest control in Brazil, where phosphorus (P) availability and nitrogen (N) leaching are among the most severe limitations for agriculture. Microbes play an important role in nutrient cycling and solubilizing of phosphate. BR, microbial biomass, population growth and the microbe's efficiency (expressed by the metabolic quotient) increased linearly and significantly with increasing charcoal concentrations (50, 100 and 150 g kg⁻¹ soil). Application of PA caused a sharp increase in all parameters. We suppose that the condensates from smoke contain easily degradable substances and only small amounts of inhibitory agents, which could be utilized by the microbes for their metabolism.  相似文献   

Groundwater level controls CO2, N2O and CH4 fluxes of three different hydromorphic soil types of a temperate forest ecosystem     

Hermann F. Jungkunst  Heiner Flessa  Christoph Scherber  Sabine Fiedler 《Soil biology & biochemistry》2008,40(8):2047-2054

Hydromorphic soils should exhibit higher climate change feedback potentials than well aerated soils since soil organic matter (SOM) losses in them are predicted to be much larger than those of well aerated soils. To evaluate a combined feedback relationship between groundwater level (GWL) and total greenhouse gas (GHG) emission, a greenhouse microcosm experiment was performed by exposing three hydromorphic forest soil types that differed in carbon content to three water levels (?40, ?20 and ?5 cm) while plants were excluded. Net GHG fluxes were measured continuously. GHG concentrations plus oxygen were measured in soil air and soil water at different depths. In this study, soil type hardly affected GHG emissions but GWL did. CO₂ emissions peaked at GWL of ?40 cm and declined on average to 65 and 33% during GWL at ?20 and ?5 cm, respectively. CH₄ emissions showed the opposite pattern having the highest emission rates at GWL of ?5 cm and compared to that on average only ?3 and ?8% during GWL at ?20 and ?40 cm, respectively. The highest mean N₂O emissions were detected at the intermediate GWL of ?20 cm, whereas it is reduced on average to 18% for GWL at ?40 cm and at ?5 cm. The highest greenhouse gas emissions (in CO₂ equivalents) were calculated for GWL at ?20 cm. During GWL at ?40 cm, CO₂ equivalent fluxes were only insignificantly lower. CO₂ equivalent fluxes reduced explicitly in mean to 35% with GWL at ?5 cm. The outcome emphasizes that anaerobic SOM decomposition apparently produces a lower warming potential than aerobic SOM decomposition. Undoubtedly, hydromorphic soils have to be considered for climate–carbon feedback scenarios.  相似文献   

C and N turnover of fermented residues from biogas plants in soil in the presence of three different earthworm species (Lumbricus terrestris,Aporrectodea longa,Aporrectodea caliginosa)     

Gregor Ernst  Anne Müller  Harald Göhler  Christoph Emmerling 《Soil biology & biochemistry》2008,40(6):1413-1420

A soil microcosm experiment was performed to assess (1) the C- and N- turnover of residues from biogas plants in soils in the presence of three earthworm species (Lumbricus terrestris, Aporrectodea longa and Aporrectodea caliginosa) and (2) the resulting changes in soil chemical and microbiological properties when using these residues as fertilizer in comparison to conventional slurry. Earthworms were exposed in soils, fertilized with an equivalent amount of 120 kg of NH₄-N ha^?1 from: (1) conventional cattle slurry and (2) a fermented residue derived from cattle slurry, grass (silage) and maize. Additional treatments without slurry and earthworms were used as controls.There was considerable evidence that soils fertilized by fermented slurry comprised fewer amounts of readily available nutrients for microbial C and N turnover. We observed significant stimulation of microbial biomass, basal respiration and nitrification in treatments with conventional slurry, especially in the presence of earthworms. However, the stimulation of microbial activity by manure and earthworms were significantly lower in treatments with fermented slurry. Moreover, the results showed clear interactions between different earthworm species and manures. While the biomass of the anecic species (L. terrestris and A. longa) increased in both slurry treatments, the biomass of A. caliginosa (endogeic) decreased, with a significantly stronger biomass decline in treatments with fermented slurry. The metabolic quotients revealed microbial stress metabolism in fermented slurry treatments, predominantly in treatments with A. caliginosa. We conclude that particularly A. caliginosa and soil microorganisms competed for labile C sources in treatments with fermented slurry. An application of these residues as fertilizer might result in a reduction of microbial activity in agricultural soils and in a decline of endogeic earthworms.  相似文献   

Joint assimilation of surface soil moisture and LAI observations into a land surface model   总被引：3，自引：0，他引：3  

Joaquín Muoz Sabater  Christoph Rüdiger  Jean-Christophe Calvet  Noureddine Fritz  Lionel Jarlan  Yann Kerr 《Agricultural and Forest Meteorology》2008,148(8-9):1362-1373

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Comparison of computer assisted surgery with conventional technique for treatment of abaxial distal phalanx fractures in horses: an in vitro study     

Rossol M  Gygax D  Andritzky-Waas J  Zheng G  Lischer CJ  Zhang X  Auer JA 《Veterinary surgery : VS》2008,37(1):32-42

Objective— To (1) evaluate and compare computer-assisted surgery (CAS) with conventional screw insertion (conventional osteosynthesis [COS]) for treatment of equine abaxial distal phalanx fractures; (2) compare planned screw position with actual postoperative position; and (3) determine preferred screw insertion direction.
Study design— Experimental study.
Sample population— Cadaveric equine limbs (n=32).
Methods— In 8 specimens each, a 4.5 mm cortex bone screw was inserted in lag fashion in dorsopalmar (plantar) direction using CAS or COS. In 2 other groups of 8, the screws were inserted in opposite direction. Precision of CAS was determined by comparison of planned and actual screw position. Preferred screw direction was also assessed for CAS and COS.
Results— In 4 of 6 direct comparisons, screw positioning was significantly better with CAS. Results of precision analysis for screw position were similar to studies published in human medicine. None of evaluated criteria identified a preferred direction for screw insertion.
Conclusion— For abaxial fractures of the distal phalanx, superior precision in screw position is achieved with CAS technique compared with COS technique.
Clinical Relevance— Abaxial fractures of the distal phalanx lend themselves to computer-assisted implantation of 1 screw in a dorsopalmar (plantar) direction. Because of the complex anatomic relationships, and our results, we discourage use of COS technique for repair of this fracture type.  相似文献   

Effects of a low dose infusion of racemic and S-ketamine on the nociceptive withdrawal reflex in standing ponies     

Peterbauer C  Larenza PM  Knobloch M  Theurillat R  Thormann W  Mevissen M  Spadavecchia C 《Veterinary anaesthesia and analgesia》2008,35(5):414-423

ObjectiveTo investigate the effect of plasma concentrations obtained by a low dose constant rate infusion (CRI) of racemic ketamine or S-ketamine on the nociceptive withdrawal reflex (NWR) in standing ponies.Study designProspective, blinded, cross-over study.AnimalsSix healthy 5-year-old Shetland ponies.MethodsPonies received either 0.6 mg kg⁻¹ racemic ketamine (group RS) or 0.3 mg kg⁻¹ S-ketamine (group S) intravenously (IV), followed by a CRI of 20 μg kg⁻¹minute⁻¹ racemic ketamine (group RS) or 10 μg kg⁻¹minute⁻¹ S-ketamine (group S) for 59 minutes. The NWR was evoked by transcutaneous electrical stimulation of a peripheral nerve before drug administration, 15 and 45 minutes after the start of the bolus injection and 15 minutes after the end of the CRI. Electromyographic responses were recorded and analysed. Arterial blood was collected before stimulation and plasma concentrations of ketamine and norketamine were measured enantioselectively using capillary electrophoresis. Ponies were video recorded and monitored to assess drug effects on behaviour, heart rate (HR), mean arterial blood pressure (MAP) and respiratory rate.ResultsThe NWR was significantly depressed in group RS at plasma concentrations between 20 and 25 ng mL⁻¹ of each enantiomer. In group S, no significant NWR depression could be observed; plasma concentrations of S-ketamine (9–15 ng mL⁻¹) were lower, compared to S-ketamine concentrations in group RS, although this difference was not statistically significant. Minor changes in behaviour, HR and MAP only occurred within the first 5–10 minutes after bolus drug administration in both groups.ConclusionAntinociceptive activity in standing ponies, demonstrated as a depression of the NWR, could only be detected after treatment with racemic ketamine. S-ketamine may have lacked this effect as a result of lower plasma concentrations, a more rapid metabolism or a lower potency of S-ketamine in Equidae so further investigation is necessary.  相似文献   

Ultra‐thin sectioning and grinding of epoxy plastinated tissue     

Mircea Constantin Sora  Christoph von Horst  Octavio Lpez-Albors  Rafael Latorre 《Anatomia, histologia, embryologia》2019,48(6):564-571

With classical sheet plastination techniques such as E12, the level and thickness of the freeze‐cut sections decide on what is visible in the final sheet plastinated sections. However, there are other plastination techniques available where we can look for specific anatomical structures through the thickness of the tissue. These techniques include sectioning and grinding of plastinated tissue blocks or thick slices. The ultra‐thin E12 technique, unlike the classic E12 technique, starts with the plastination of a large tissue block. High temperatures (30–60°C) facilitate the vacuum‐forced impregnation by decreasing the viscosity of the E12 and increasing the vapour pressure of the intermediary solvent. By sectioning the cured tissue block with a diamond band saw plastinated sections with a thickness of <300 μm can be obtained. The thickness of plastinated sections can be further reduced by grinding. Resulting sections of <100 µm are suitable for histological staining and microscopic studies. Anatomical structures of interest in thick plastinate slices can be followed by variable manual grinding in a method referred to as Tissue Tracing Technique (TTT). In addition, the tissue thickness can be adapted to the transparency or darkness of tissue types in different regions of the same plastinated section. The aim of this study was to evaluate the advantages of techniques based on sectioning and grinding of plastinated tissue (E12 ultra‐thin and TTT) compared to conventional sheet‐forming techniques (E12).  相似文献