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561.
Puglisi Edoardo Zaccone Claudio Cappa Fabrizio Cocconcelli Pier Sandro Shotyk William Trevisan Marco Miano Teodoro M. 《Biology and Fertility of Soils》2014,50(5):815-826
Biology and Fertility of Soils - Peatlands are archives of extreme importance for the assessment of past ecological, environmental and climatic changes. The importance as natural archives is even... 相似文献
562.
Zooplankton reside in a constantly flowing environment. However, information about their response to ambient flow has remained elusive, because of the difficulties of following the individual motions of these minute, nearly transparent animals in the ocean. Using a three-dimensional acoustic imaging system, we tracked >375,000 zooplankters at two coastal sites in the Red Sea. Resolution of their motion from that of the water showed that the animals effectively maintained their depth by swimming against upwelling and downwelling currents moving at rates of up to tens of body lengths per second, causing their accumulation at frontal zones. This mechanism explains how oceanic fronts become major feeding grounds for predators and targets for fishermen. 相似文献
563.
Alessio Varesano Annalisa Aluigi Claudio Tonin Franco Ferrero 《Fibers and Polymers》2006,7(2):105-111
Coating the fibre surface byin situ oxidative chemical polymerisation of polypyrrole (using FeCl3 as oxidant) is a readily industrial applicable way to give electrical properties to wool with good ageing stability [1],
although pre-treatments are required to avoid damage of the cuticle surface due to the acidic condition of the process. FT-IR
and EDX analysis reveal that organic sulphonates and sulphates, used as dopants, are absorbed by wool, while chlorine ions
are preferably embedded on the polypyrrole layer. The resulting electrical conductivity seems mainly due to the presence of
chlorine as counter-ion of polypyrrole; nevertheless, the presence of arylsulphonate in the polymerisation bath increases
the electrical conductivity of the coating layer. 相似文献
564.
Bussadori C Pradelli D Borgarelli M Chiavegato D D'Agnolo G Menegazzo L Migliorini F Santilli R Zani A Quintavalla C 《Veterinary journal (London, England : 1997)》2009,182(2):187-192
This prospective study was conducted to evaluate the prevalence and severity of ocular lesions in dogs with anemia (packed cell volume 20%) and/or thrombocytopenia (platelet count < 150,000/μL). Dogs were divided into four groups: (1) anemic (n = 17); (2) thrombocytopenic (n = 36); (3) anemic and thrombocytopenic (n = 24); and (4) healthy controls (n = 26). The prevalence of ophthalmic lesions in these four groups was 12%, 42%, 42% and 0%, respectively. Anemia was not associated with the presence of ocular lesions (P = 0.41) or their severity. Thrombocytopenia was significantly associated with the presence of ocular lesions (P = 0.0016) and with their severity (P = 0.017). We conclude that thrombocytopenia, but not anemia, is associated with ocular lesions in dogs. 相似文献
565.
Viliana Vasileva Konstantina Kocheva Janet Mincheva Georgi Georgiev Anna Ilieva Claudio Porqueddu 《Journal of plant nutrition》2017,40(15):2116-2126
Growth and physiological parameters of intercropped subterranean clover (Trifolium subterraneum L.) and cocksfoot (Dactylis glomerata L.) were investigated under controlled and field conditions. Nitrogen nutrition was accomplished in symbiotic and heterotrophic forms in both the species studied under controlled concentration of mineral elements in the media and by in oculation with appropriate rhizobial strain. Intercropped variants were also grown in sand culture as follows: subterranean clover – 100%, cocksfoot – 100%, subterranean clover:cocksfoot– 75:25(%), subterranean clover: cocksfoot– 50:50(%), and subterranean clover:cocksfoot– 25:75(%). In hydroponic cultures, subterranean clover to cocksfoot proportion was always 50:50(%). Subterranean clover reacted positively with growth up to 1.25 mM nitrate concentration in the medium with stimulation of number of nodules formed and their nitrogenase activity. When separately grown, both subclover and cocksfoot reacted with higher plant biomass formation under higher nitrate nutrition. When intercropped, the process of growth stimulation in subclover was more prominent than in cocksfoot. 相似文献
566.
Review on iron availability in soil: interaction of Fe minerals,plants, and microbes 总被引:1,自引:0,他引:1
Claudio Colombo Giuseppe Palumbo Ji-Zheng He Roberto Pinton Stefano Cesco 《Journal of Soils and Sediments》2014,14(3):538-548
Purpose
The rationale of this paper is to review the state of the art regarding the biotic and abiotic reactions that can influence Fe availability in soils. In soil, the management-induced change from oxic to anoxic environment results in temporal and spatial variations of redox reactions, which, in turn, affect the Fe dynamics and Fe mineral constituents. Measuring the Fe forms in organic complexes and the interaction between bacteria and Fe is a major challenge in getting a better quantitative understanding of the dynamics of Fe in complex soil ecosystems.Materials and methods
We review the existing literature on chemical and biochemical processes in soils related with the availability of Fe that influences plant nutrition. We describe Fe acquisition by plant and bacteria, and the different Fe–organic complexes in order to understand their relationships and the role of Fe in the soil carbon cycle.Results and discussion
Although total Fe is generally high in soil, the magnitude of its available fraction is generally very low and is governed by very low solubility of Fe oxides. Plants and microorganisms can have different strategies in order to improve Fe uptake including the release of organic molecules and metabolites able to form complexes with FeIII. Microorganisms appear to be highly competitive for Fe compared with plant roots. Crystalline Fe and poorly crystalline (hydro)oxides are also able to influence the carbon storage in soil.Conclusion
The solubility of crystalline Fe minerals in soil is usually very low; however, the interaction with plant, microbes, and organic substance can improve the formation of soluble FeIII complexes and increase the availability of Fe for plant growth. Microbes release siderophores and plant exudates (e.g., phytosiderophores, organic acids, and flavonoids), which can bind and solubilize the Fe present in minerals. The improved understanding of this topic can enable the identification of effective solutions for remedying Fe deficiency or, alternatively, restricting the onset of its symptoms and yield’s limitations in crops. Therefore, development and testing of new analytical techniques and an integrated approach between soil biology and soil chemistry are important prerequisites. 相似文献567.
We studied physiological (gas exchange and stomatal aperture) and morphological (individual leaf area and stomatal density) responses in leaves of five-year-old olive plants (Olea europaea L. cvs. Frantoio and Moraiolo) exposed to filtered air containing < 3 ppb O(3) or 100 ppb O(3) for 5 h day(-1) for 120 days in fumigation chambers. After 100 days of treatment, leaf drop and development of necrotic spots were observed in O(3)-fumigated plants of Moraiolo but not of Frantoio. Significant reductions in photosynthetic activity (57%) and stomatal conductance (69%) were detected in O(3)-fumigated plants of Frantoio compared with control plants. In O(3)-fumigated plants of Moraiolo, the decrease in photosynthetic activity (17%) was not statistically significant, but a significant reduction in stomatal conductance (40%) was observed. In both cultivars, leaves that developed after exposure to O(3) showed decreased stomatal aperture (63.6 and 54.8% with respect to the Frantoio and Moraiolo controls, respectively) and one-sided leaf area, and increased stomatal density compared with control leaves. Actual transpiring stomatal surface decreased substantially in both Frantoio (59.8%) and Moraiolo (56.3%) in response to O(3) treatment. Relative transpiring stomatal surface (RTSS) in Frantoio decreased from 0.54 (control) to 0.27% (O(3) treated) of total leaf surface. The corresponding values for Moraiolo were 0.79 and 0.42%. However, because the RTSS of Moraiolo leaves in the O(3) treatment was 0.42 versus 0.27% in Frantoio, the potential uptake of O(3) was higher for Moraiolo plants than for Frantoio plants. The large O(3)-induced reduction in transpiring stomatal surface in both cultivars could have significant effects on olive productivity in the Mediterranean area, where high O(3) concentrations persist for long periods during the year. 相似文献
568.
Nicolás Franck Sylvia Winkler Claudio Pastenes Rodrigo Infante 《Agroforestry Systems》2007,69(3):215-229
Murta (Ugni molinae Turcz.) is an evergreen shrub of the native forest understorey of southern Chile that produces berries which are consumed
in the local markets. Because of the natural adaptation of murta to growing under the shade of trees, we propose that an adequate
way of domesticating this species would be its cultivation in agroforestry systems. In order to assess the suitability of
three murta accessions from different regions in southern Chile for their cultivation in such systems, we established a trial
in which these accessions were submitted to six light transmittance levels (20%–100% of full solar irradiance) from planting
in spring to the following autumn. Optimum growth, as assessed through dry mass accumulation and emission of branches and
metamers, was achieved at moderate light transmittance levels (50%–65%). These growth traits showed stable positive responses
to the relative amount of light intercepted by the plants (as estimated from plant structural traits) up to these optimum
light transmittance levels and diverged to lower values thereafter. These stable relationships suggest that the differences
in plant growth at low and moderate light transmittance levels can be attributed to restrictions of photosynthesis by light
availability. The reduction in growth for higher light transmittance levels may be partly attributed to photoinhibition as
suggested by reduced chlorophyll content and relatively low increments in carotenoid content in leaves at high light transmittance
levels. 相似文献