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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Grass and forage science 46 (1991), S. 0 
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Ryegrass, some white clover cultivars (Grasslands Huia, Trifo, Barbian and Luclair) and lotus were grown in the presence of mineral nitrogen and at a range of phosphorus (P) supply. Ryegrass had the highest leaf inorganic P concentrations on a dry weight basis, and lotus the lowest. In the clovers and lotus shoot yield was correlated with inorganic P concentration; it was not correlated in ryegrass, although this was possibly a result of the stage of development of ryegrass when it was harvested. Ryegrass was always more efficient than the legumes in acquiring P and growing rapidly. When inorganic P concentration was expressed on the basis of DNA, lotus had concentrations intermediate between that of ryegrass and the clovers, i.e. lotus had at least as much inorganic P per unit of DNA as white clover. It is suggested that although lotus is more efficient than white clover in terms of the concentration of inorganic P on a dry weight basis, the amount of inorganic P required per ‘module of metabolism’ (or cell), is similar. Lotus also has larger cells than white clover and the relatively greater efficiency of lotus may lie at least partly in its ability to achieve an equivalent leaf area or weight with fewer cells, i.e. cytology contributes to efficiency.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Grass and forage science 47 (1992), S. 0 
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Two cultivars of white clover (Ladino and Kent Wild White) and two cultivars of lotus (Grasslands Maku and G4703) were grown in pots of soil at low to moderate levels of phosphorus (P) supply. Nitrogen supply was by fixation. Cell size and nitrogen, phosphorus and chlorophyll content per cell were estimated from samples of leaf tissue. Maku lotus had larger cells and higher cellular contents of metabolites than the clovers. These measurements support earlier suggestions that, compared with white clover, the higher P-efficiency (dry matter per unit of internal P) of Maku lotus may be explained by cytological factors without recourse to explanations based on differences in nutrient metabolism. The relatively large cells and high metabolite levels per cell of Maku lotus appear to arise from its creation as an artificial tetraploid.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Grass and forage science 49 (1994), S. 0 
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: White clover (Grasslands Huia) and lotus (Grasslands Maku) were grown in pots of soil at a range of phosphorus supply, and reliant on symbiotic nitrogen fixation (SN plants) or entirely on mineral nitrogen (MN plants). Shoots increased in weight with phosphorus supply. White clover MN shoots were bigger than those of SN plants except at the lowest level of phosphorus supply; lotus MN shoots were only bigger than SN shoots at the highest level of phosphorus supply. Leaf growth rate and size increased with phosphorus supply but were not significantly affected by the nitrogen treatments.Estimates of cell size were made by determining DNA concentration, by digestion of tissue followed by counting and by taking vinyl impressions of epidermal cell surfaces. Lotus cells are bigger than those of white clover. ‘Digested’ cell sizes were not significantly affected by changes in phosphorus supply. Epidermal cell size increased with phosphorus supply, but the relationship was weaker in SN than in MN plants. Methods which give values for ‘average’ cell size are capable of detecting large-scale differences, but methods able to resolve cell heterogeneity are necessary for an accurate picture of the relationship between leaf growth and cellular nutrition.Average concentrations of total and inorganic phosphorus on a DNA basis did not differ between the species, contrary to concentrations on a dry weight basis, indicating that differences in phosphorus efficiency can be partly explained on the basis of average differences in cell size. Differences in inorganic phosphorous on a DNA basis at higher levels of supply suggested an additional intrinsic difference in cellular accumulation of inorganic phosphorus between the two species.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 16 (2002), S. 0 
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The gut flora is a vast interior ecosystem whose nature is only beginning to be unravelled, due to the emergence of sophisticated molecular tools. Techniques such as 16S ribosomal RNA analysis, polymerase chain reaction amplification and the use of DNA microarrays now facilitate rapid identification and characterization of species resistant to conventional culture and possibly unknown species. Life-long cross-talk between the host and the gut flora determines whether health is maintained or disease intervenes. An understanding of these bacteria–bacteria and bacteria–host immune and epithelial cell interactions is likely to lead to a greater insight into disease pathogenesis. Studies of single organism–epithelial interactions have revealed the large range of metabolic processes that gut bacteria may influence. In inflammatory bowel diseases, bacteria drive the inflammatory process, and genetic predisposition to disease identified to date, such as the recently described NOD2/CARD15 gene variants, may relate to altered bacterial recognition. Extra-intestinal disorders, such as atopy and arthritis, may also have an altered gut milieu as their basis. Clinical evidence is emerging that the modification of this internal environment, using either antibiotics or probiotic bacteria, is beneficial in preventing and treating disease. This natural and apparently safe approach holds great appeal.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 73 (1988), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Net photosynthesis, concurrent carbon export and starch, sucrose and inorganic phosphorus concentrations were measured in leaves of white clover (Trifolium repens L. cv. Grasslands Huia) grown at four levels of phosphorus supply in the presence or absence of mineral nitrogen. The nitrogen treatments had no effect on growth, photosyntheis or carbon export. At the three higher levels of phosphorus supply, the amount of carbon exported was about 77% of net fixation. Photosynthesis and export per leaf decreased with phosphorus supply, primarily through the effect of phosphorus supply on leaf area. The rate of photosynthesis was reduced only at the lowest level of phosphorus supply.Inorganic phosphorus rose with phosphorus supply but starch concentration was unaffected. Sucrose was reduced at the lowest level of phosphorus supply but not significantly affected at higher levels. The ratio between starch and sucrose concentration was also unaffected at the higher levels, but was increased at the lowest level of supply. There thus appeared to be direct effects of phosphorus supply on photosynthesis, partitioning of carbon to carbohydrates and, by implication, export, only at the lowest level of phosphorus supply. As leaf area and plant growth were affected over the whole range of phosphorus supply, factors other than photosynthesis per se must have determined the response of growth to phosphorus supply.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 61 (1984), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: ‘Grasslands Huia’ white clover (Trifolium repens L.), ‘Grasslands Maku’ lotus (Lotus pedunculatus Cav.) and suckling clover (T. dubium Sibth) were grown in a controlled environment at various levels of P supply. Dry weights and the concentration of inorganic-, lipid-, ester- and residual-P in trifoliate leaves were measured. Lotus grew better than white or suckling clover at low P. White clover and lotus responded steeply to increased P and had similar shoot dry weights at high P. Suckling clover had lower shoot weights than the other species at all P levels. The superior growth of lotus at low levels of p was probably due to better root growth and P uptake. Lotus had higher shoot P concentrations at low levels of P but lower concentrations than the others at high levels. White clover and suckling clover had similar shoot P concentrations at all levels of supply. In white and suckling clover total leaf P concentration rose with P supply. Of the P fractions, inorganic-and residual-P showed the largest rises in concentration. The increases in lipid- and ester-P were smaller. Increases in lotus leaf P were small, primarily because of the relatively small rises in inorganic- and residual-P. White clover is a vigorous species but requires high levels of P for best growth. Suckling clover has a relatively small response to improvements in P availability. The behaviour of the various P fractions is similar to that in white clover. Lotus grows well at low P but also shows rapid growth at high P supply. Whether efficiency is defined as the ability to extract P from the environment or to maintain low internal P concentration, lotus makes efficient use of P over the whole range of P supply.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 20 (2004), S. 0 
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background : Forty per cent of patients with inflammatory bowel disease fail to respond to standard dose azathioprine (2 mg/kg/day).Aims : To evaluate the efficacy and safety of increasing the azathioprine dose according to a fixed schedule and guided by clinical response and adverse effects.Methods : We reviewed the records of all patients with inflammatory bowel disease treated by a single clinician over 6 years, unresponsive to at least 3 months treatment with standard dose azathioprine, and whose dose was subsequently increased.Results : Forty patients (27 male; 24 Crohn's, 16 ulcerative colitis) with chronic active disease or recurrent flares despite standard dose azathioprine for a median 8 months (range 3–114) increased their dose from a median 2.02 (1.61–3.19) mg/kg/day to 2.72 (2.37–3.99) mg/kg/day in one to four increments of 0.5 mg/kg/day, and were followed over a median6 (0.5–54) months. Eleven of the 40 patients (seven Crohn's, four ulcerative colitis) responded or had reduced frequency of flare-ups at the end of follow-up, while 17 of the 40 patients had no benefit. Response was more likely for maximum doses ≤2.5 mg/kg/day (six of 11 patients) than for doses 〉2.5 mg/kg/day (five of 29 patients) (P = 0.042). Twelve patients (11 of whom received maximum doses 〉2.5 mg/kg/day) were unable to maintain an increased azathioprine dose because of leukopenia in eight, nausea in three, and raised liver enzymes in one (all transient and reversible).Conclusions : Increasing the azathioprine dose up to 2.5 mg/kg/day appears beneficial in patients who have not responded to 2 mg/kg/day. Further increase above 2.5 mg/kg/day is less likely to be efficacious, and is associated with a substantial risk of adverse reactions.
    Type of Medium: Electronic Resource
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