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131.
Hatchery cultivation of the common cockle (Cerastoderma edule L.): from conditioning to grow‐out 下载免费PDF全文
Anna Elisabeth Pronker Frank Peene Silke Donner Sander Wijnhoven Pieter Geijsen Peter Bossier Nancy Marie Nevejan 《Aquaculture Research》2015,46(2):302-312
This study describes for the first time the cultivation of Cerastoderma edule on a commercial scale. A protocol to grow F2 generation cockles was developed, which led to fine‐tuning experiments for broodstock conditioning and spat growth. Broodstock animals were conditioned with diets of Isochrysis galbana (T‐Iso) or Tetraselmis suecica, whereas a third group was not fed. The best diet, T. suecica, induced 12 females out of 100 animals to spawn a total of 3 380 000 eggs. The non‐fed group did not spawn. Cockle spat (4.9 ± 1.0 mm) grew best when given a mixed diet of C. muelleri, T‐Iso and Sceletonema costatum, or a mixture of P. tricornutum and S. costatum at a concentration of 240 cells μl?1 day?1, resulting in a tripling of their wet weight after 14 days. The impact of density, burrowing substrate and food availability on cockle spat growth (41 days old, 5.6 ± 1.2 mm) was studied for 11 weeks. Best results were obtained by culturing spat at ad libitum food conditions at 500 ind m?2, resulting in an average growth rate of 168 μm day?1, an average final size of 19.0 ± 1.9 mm and a total final biomass of 1040 g m?2. 相似文献
132.
Peiffer Stefan Beierkuhnlein Carl Sandhage-Hofmann Alexandra Kaupenjohann Martin Bär Silke 《Water, air, and soil pollution》1997,94(3-4):401-416
A field study was performed on the effects of acid mine leachate from slate mine tailings seeping into a small river passing through the tailings. Before entering the tailings the river water has high alkalinity which neutralizes acidity upon mixing with leachate within the tailings. Donwstreams of the tailings the pH of the river water ranges about pH = 8, the water contains high concentrations of sulfate (≈1500 μmol/1 and particulate bound aluminium (≈80 μmol/I), but low concentrations of dissolved aluminium (≈3 μmol/1). It is therefore assumed that AI(OH)3 colloids are precipitated during the neutralisation process and transported out of the tailings. The concentration of particulate bound aluminium along the river shows a strong correlation with the concentration of sulfate, which indicates that particulate bound aluminium is conservative. It therefore seems that under dry weather conditions (under most of the sampling was performed) no chemical retention mechanism exists which confines the distribution of aluminium to a restricted part of the catchment area. In contrast, the white river sediment is rich in both aluminium and sulfate, which suggests the temporary formation of aluminium hydroxosulfate minerals. Favorable (i.e. acidic) conditions may prevail at high discharges where the acidity accumulated in the tailings is flushed into the river with its subsequent acidification. 相似文献
133.
Climate change with increasing temperature and ocean acidification (OA) poses risks for marine ecosystems. According to Pörtner and Farrell [1], synergistic effects of elevated temperature and CO2-induced OA on energy metabolism will narrow the thermal tolerance window of marine ectothermal animals. To test this hypothesis, we investigated the effect of an acute temperature rise on energy metabolism of the oyster, Crassostrea gigas chronically exposed to elevated CO2 levels (partial pressure of CO2 in the seawater ~0.15 kPa, seawater pH ~ 7.7). Within one month of incubation at elevated Pco2 and 15 °C hemolymph pH fell (pHe = 7.1 ± 0.2 (CO2-group) vs. 7.6 ± 0.1 (control)) and Peco2 values in hemolymph increased (0.5 ± 0.2 kPa (CO2-group) vs. 0.2 ± 0.04 kPa (control)). Slightly but significantly elevated bicarbonate concentrations in the hemolymph of CO2-incubated oysters ([HCO− 3]e = 1.8 ± 0.3 mM (CO2-group) vs. 1.3 ± 0.1 mM (control)) indicate only minimal regulation of extracellular acid-base status. At the acclimation temperature of 15 °C the OA-induced decrease in pHe did not lead to metabolic depression in oysters as standard metabolism rates (SMR) of CO2-exposed oysters were similar to controls. Upon acute warming SMR rose in both groups, but displayed a stronger increase in the CO2-incubated group. Investigation in isolated gill cells revealed a similar temperaturedependence of respiration between groups. Furthermore, the fraction of cellular energy demand for ion regulation via Na+/K+-ATPase was not affected by chronic hypercapnia or temperature. Metabolic profiling using 1H-NMR spectroscopy revealed substantial changes in some tissues following OA exposure at 15 °C. In mantle tissue alanine and ATP levels decreased significantly whereas an increase in succinate levels was observed in gill tissue. These findings suggest shifts in metabolic pathways following OA-exposure. Our study confirms that OA affects energy metabolism in oysters and suggests that climate change may affect populations of sessile coastal invertebrates such as mollusks. 相似文献
134.
Inversion of a canopy reflectance model using hyperspectral imagery for monitoring wheat growth and estimating yield 总被引:2,自引:0,他引:2
Silke Migdall Heike Bach Jans Bobert Marc Wehrhan Wolfram Mauser 《Precision Agriculture》2009,10(6):508-524
Applications of hyperspectral remote sensing data to derive relevant properties for precision agriculture are described. Green
leaf area index, fraction of senescent material and grain yield are retrieved from the hyperspectral data. Two sensors were
used to obtain these data; the airborne visible/infrared imaging spectrometer AVIS and the space-borne compact high-resolution
imaging spectrometer CHRIS; they show the applicability of the methods to different spatial scales. In addition, the bi-directional
observation capability of the CHRIS sensor is used to derive information about the average leaf angle of the canopies which
are used to link canopy structure with phenological development. Derivation of the canopy properties, green leaf area index
and fraction of senescent material was done with the radiative transfer model, SLC (soil–leaf–canopy). The results were used
as input into the crop growth model PROMET-V to calculate grain yield. Two years of data from the German research project
preagro are presented. 相似文献
135.
Wolfgang Merbach Edith Mirus Günther Knof Rainer Remus Silke Ruppel Rolf Russow Andreas Gransee Joachim Schulze 《植物养料与土壤学杂志》1999,162(4):373-383
The root-borne C- and N-flux in the plant/soil system was studied by determining the 14C- or 15N-balances in pot trials with soil as a substrate (14CO2- or 15NH3-application to the shoots, comparison of sterile and nonsterile treatments for quantification of root-borne substances). The following results were obtained: 1. The amount of (primary) root-borne carbon compounds released into soil was (besides root respiration) 11—20% of net-CO2-assimilation or 13—32% of the 14C incorporated into the plants (= 1 t C · ha—1). 5—6% of 15N assimilated by the plants were released as root-borne N compounds (= 15 kg N · ha—1). 2. A considerable portion of the root-borne C (about 6% = 600 kg C · ha—1) was found in the rooted soil zone at the end of the experiments (rhizodeposition). 3. (Primary) root-borne C and N compounds found in immediate vicinity of the roots (about 60—80%) were mainly water soluble, whereas most of the C and N compounds found in a greater distance were water insoluble. The water soluble exudates consisted mainly of neutral (carbohydrates) and acid fractions (organic acids). The basic fraction (amino acids) made up a small portion only. 4. The root-borne C and N compounds influenced the nutrient balance of soil and plant directly and/or indirectly via microbes (depending on species, variety and nutritional status of plants). 5. Microbes stimulated the release of C- and N-compounds, but rapidly respired 65—85% of the root-borne C-compounds, thereby putting a burden on the C-budget of the “host” plant. 6. It could be shown by the example of hup+ Rhizobium meliloti strains (tested by 3H2-incorporation) and the wheat-Serratia-association, that energy efficient microbenplant systems can improve plant performance. 相似文献
136.
Does long-term farmyard manure fertilization affect short-term nitrogen mineralization from farmyard manure? 总被引:2,自引:0,他引:2
Leif Nett Sven Averesch Silke Ruppel Jörg Rühlmann Carmen Feller Eckhard George Matthias Fink 《Biology and Fertility of Soils》2010,46(2):159-167
One of the challenges in organic farming systems is to match nitrogen (N) mineralization from organic fertilizers and crop
demand for N. The mineralization rate of organic N is mainly determined by the chemical composition of the organic matter
being decomposed and the activity of the soil microflora. It has been shown that long-term organic fertilization can affect
soil microbial biomass (MB), the microbial community structure, and the activity of enzymes involved in the decomposition
of organic matter, but whether this has an impact on short-term N mineralization from recently applied organic substances
is not yet clear. Here, we sampled soils from a long-term field experiment, which had either not been fertilized, or fertilized
with 30 or 60 t ha−1 year−1 of farmyard manure (FYM) since 1989. These soil samples were used in a 10-week pot experiment with or without addition of
FYM before starting (recent fertilization). At the start and end of this experiment, soil MB, microbial basal respiration,
total plant N, and mineral soil N content were measured, and a simplified N balance was calculated. Although the different
treatments used in the long-term experiment induced significant differences in soil MB, as well as total soil C and N contents,
the total N mineralization from FYM was not significantly affected by soil fertilization history. The amount of N released
from FYM and not immobilized by soil microflora was about twice as high in the soil that had been fertilized with 60 t ha−1 year−1 of FYM as compared with the non-fertilized soil (p < 0.05). 相似文献
137.
138.
Janin Reifenrath Daniel Gottschalk Nina Angrisani Silke Besdo Andrea Meyer-Lindenberg 《Acta veterinaria Scandinavica》2012,54(1):21
Background
Different animal models are used as fracture models in orthopaedic research prior to implant use in humans, although biomechanical forces can differ to a great extend between species due to variable anatomic conditions, particularly with regard to the gait. The rabbit is an often used fracture model, but biomechanical data are very rare. The objective of the present study was to measure axial forces, bending moments, and bending axis directly in the rabbit tibia in vivo. The following hypothesis was tested: Axial forces and bending moments in the mid-diaphysis of rabbit tibia differ from other experimental animals or indirectly calculated data.Methods
A minifixateur system with 4 force sensors was developed and attached to rabbit tibia (n = 4), which were subsequently ostectomised. Axial forces, bending moments and bending angles were calculated telemetrically during weight bearing in motion between 6 and 42 days post operation.Results
Highest single values were 201% body weight [% bw] for axial forces and 409% bw cm for bending moments. Whereas there was a continous decrease in axial forces over time after day 10 (P = 0.03 on day 15), a decrease in bending moments was inconsistent (P = 0.03 on day 27). High values for bending moments were frequently, but not consistently, associated with high values for axial forces.Conclusion
Axial forces in rabbit tibia exceeded axial forces in sheep, and differed from indirectly calculated data. The rabbit is an appropriate fracture model because axial loads and bending moments in rabbit tibia were more closely to human conditions than in sheep tibia as an animal model. 相似文献139.
Schmitz S Garden OA Werling D Allenspach K 《Veterinary immunology and immunopathology》2012,146(1):87-91
Inflammatory bowel disease (IBD) is a common cause of chronic diarrhoea in dogs. In people, specific cytokine patterns attributed to T cell subsets, especially T helper cell [Th]1, Th17 and regulatory T(reg) cells have emerged in IBD. In contrast, no specific involvement of a distinct T cell subset has been described so far in canine IBD. Thus, the aim of the present study was to assess gene expression of signature cytokines in duodenal tissues from 18 German shepherd dogs with IBD (group 1), 33 dogs of other breeds with IBD (group 2) and 15 control dogs (group 3). Relative quantification of IL-17A, IL-22, IL-10, IFNy and TGFβ was performed. Expression of IL-17A was significantly lower in groups 1 and 2 compared to group 3 (p=0.014), but no difference in the expression of IL-22 (p=0.839), IFNγ (p=0.359), IL-10 (p=0.085) or TGFβ (p=0.551) across groups was detected. Thus, no clear evidence for the involvement of Th-17 signature cytokines in canine IBD at the mRNA level could be shown. The contribution of specific T cell subsets to the pathogenesis of canine IBD warrants further investigation. 相似文献
140.
Silke Steinmöller Martina Bandte Carmen Büttner Petra Müller 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(3):753-763
The two quarantine pests Synchytrium endobioticum, the causal agent of potato wart disease and Globodera rostochiensis, the yellow potato cyst nematode are currently present in Germany. Winter sporangia of Synchytrium endobioticum and cysts of Globodera rostochiensis can be spread with waste from potato processing industries, if infected tubers are processed. The German Biowaste Ordinance prescribes sanitation of organic waste before it can be used on arable land as fertilizer or filling material. Sanitation parameters prescribed by the German Biowaste Ordinance include composting for 7 days at 65°C or 14 days at 55°C or pasteurisation for 60 min at 70°C. The effect of composting and pasteurisation processes on winter sporangia of Synchytrium endobioticum and cysts of Globodera rostochiensis was tested with varying time-temperature relations. Cysts of Globodera rostochiensis were killed by composting for 7 days at 50–55°C and by pasteurisation for 30 min at 70°C. In contrast, viable winter sporangia of Synchytrium endobioticum could be extracted from sample material after composting for 70 days at 30–45°C, composting for 21 days at 50–55°C and after composting for 12 days at 60–65°C. Likewise viable winter sporangia could be extracted after pasteurisation for 90 min at 70°C and heating in a water bath at 80°C and in a dry oven at 90°C for 8 h. The parameters prescribed in the German Biowaste Ordinance are sufficient to kill cysts of Globodera rostochiensis but not sufficient to kill winter sporangia of Synchytrium endobioticum in organic waste. 相似文献