The benzimidazole anthelmintic agents-a review   总被引：4，自引：0，他引：4  

Q. A. McKELLAR  E. W. SCOTT 《Journal of veterinary pharmacology and therapeutics》1990,13(3):223-247

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Leaf photosynthesis is enhanced in normal oil maize pollinated by high oil maize hybrids     

R.F. Wang  D.G. An  Q.E. Xie  G.M. Jiang  K.J. Wang 《Industrial Crops and Products》2009,29(1):182-188

The grain yield of normal oil maize (Zea mays L.) might increase when pollinated by high oil maize (HOM) hybrids because of heterosis. To testify that the grain yield increase might be a result of improved photosynthetic rate and related traits, the normal oil maize (NOM) hybrid, Nongda108, was cross-pollinated by three HOM hybrids, HOM202, HOM115 and HOM4515 (for short as ND108pHOM202, ND108pHOM115 and ND108pHOM4515). We found that the ND108pHOM202 and ND108pHOM115 exhibited higher net photosynthetic rate (P_n), accompanied by larger stomatal conductance (g_s) and transpiration rate (E). Moreover, delayed leaf senescence was observed in their leaves, including larger leaf area index (LAI) and higher Chl content and Chl a/b ratio. Apart from higher phosphoenolpyruvate carboxylase (PEPCase) activity, the soluble proteins were also higher in the two cross-pollinations. The higher leaf photosynthesis could explain the grain increase in ND108pHOM202 and ND108pHOM115. However, ND108pHOM4515 exhibited a decreased photosynthetic characteristic and yield performance. Significantly positive relation between grain yield and biomass (r² = 0.96, P < 0.05), P_n and biomass (r² = 0.74, P < 0.05) also suggested that the yield increase in the two cross-pollination treatments was generally owing to the higher photosynthetic rate and related photosynthetic traits.  相似文献   

The occurrence of and organisms concerned with bovine mycotic abortion in some counties of Ireland     

J. J. Sheridan  D. S. C. White  Q. D. McGarvie 《Veterinary research communications》1985,9(1):221-226

Bovine mycotic abortion in some counties of the Irish provinces of Leinster and Ulster was estimated at 1–2% of all abortions for which a causal agent was identified in the years from 1969 to 1978. The organism most commonly isolated from diseased specimens wasAspergillus fumigatus, followed byAbsidia corymbifera. There was no relationship between the incidence of the disease in any year and the rainfall or number of raindays during the previous summer. The data obtained are discussed in relation to the occurrence of the disease in the United Kingdom.  相似文献   

Water-table management in lowland UK peat soils and its potential impact on CO₂ emission     

C. Kechavarzi    Q. Dawson    P. B. Leeds-Harrison  J. Szaty&#;owicz  & T. Gnatowski 《Soil Use and Management》2007,23(4):359-367

The rate of oxidation of peat soils is highly seasonal and varies with temperature and soil moisture content. Large variations in soil moisture content result in wet–dry cycles that can enhance peat degradation. Water‐table management plays a crucial role in controlling and damping the effect of these environmental factors. However, maintaining high ditch water levels in fields bounded by ditches does not guarantee a high field groundwater level. The effect of installing subsurface irrigation at different spacings on water table elevation was studied in a low‐lying peat grassland. The water table elevation data were compared against values predicted with a water balance model. In addition, greenhouse experiments were carried out on undisturbed soil core samples collected from the peat grassland as well as a low‐lying peatland under intensive arable faming to measure CO₂ evolution under different water regimes. The field data from the peat grassland suggest that sub‐irrigation spacing as low as 10 m is necessary during summer periods to maintain groundwater levels similar to those in the ditches. Over the same period of observation, the difference in water level between the ditches and the non‐irrigated fields is as high as 0.7 m. Modelled outputs are in good correlation with the field observations, and demonstrate that simple water balance models can provide an effective tool to study the effect of water management practices and potential changes in subsurface conditions, climate and land use on water‐table levels. The measurement of CO₂ emission from undisturbed peat soil columns shows that the rate of oxidation of soil organic matter from peat soils is highly seasonal and that drainage exacerbates the rate of peat mineralization.  相似文献   

Boekbesprekingen     

J. R. B.  Q. 《European journal of plant pathology / European Foundation for Plant Pathology》1908,14(5):139-144

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Effects of intensive harvesting on nutrient capitals of three forest types in New England     

J. W. Hornbeck  C. T. Smith  Q. W. Martin  L. M. Tritton  R. S. Pierce 《Forest Ecology and Management》1990,30(1-4):55-64

Effects of whole-tree clearcutting are being studied in three major forest types in the northeastern United States: a spruce-fir forest in central Maine, a northern hardwood forest in New Hampshire, and a central hardwood forest in Connecticut. At each site we sampled total and extractable nutrient capitals, inputs and outputs of nutrient ions in precipitation and streamflow, nutrient removals in harvested products, and nutrient accumulation in regrowth. Depending upon location, combined losses of nutrients in harvested products and increased leaching to streams were in the ranges of 374–558 kg ha⁻¹ for Ca, 135–253 kg ha⁻¹ for K, 50–65 kg ha⁻¹ for Mg, 248–379 kg ha⁻¹ for N, and 19–54 kg ha⁻¹ for P. Opportunities for replacing these losses over the next rotation are best for N. Data on inputs in precipitation versus outputs in streamflow indicate that, once effects of harvest subside, most N in precipitation will stay within the forest. By contrast, Ca shows a net output of 8–15 kg ha⁻¹ year⁻¹ from uncut watersheds, and the added leaching losses due to harvest may have a serious impact on Ca capital. This is especially the case for the Connecticut site, where total site capital for Ca is only about 4000 kg ha⁻¹.  相似文献   

Variation in the C:N ratio of substrate mineralized during forest humus decomposition     

O.Q. Hendrickson 《Soil biology & biochemistry》1985,17(4):435-440

Laboratory incubations of sieved (<2mm) forest humus were used to study the response of C and N mineralization to perturbation. Considerable variation in the ratio of mineralized C to mineralized N was observed. This ratio widened with increasing temperature. At constant temperature, addition of P stimulated CO₂-C evolution and reduced NH₄⁺-N production, also widening the C:N ratio of substrate mineralized. Addition of weak base stimulated mineralization of N more than C, reducing the C:N ratio of substrate mineralized. Addition of weak acid, mineral-N, or excessive amounts of water inhibited CO₂-C evolution while stimulating production of NH₄⁺-N, resulting in a “negative correlation” between the two, and reducing the C:N ratio of substrate mineralized still further.Results were interpreted in terms of effects on microbial biomass. A relatively benign treatment (P addition) may promote microbial growth and respiration, reducing net N availability. A moderate perturbation (addition of weak base) favors new organisms growing partly at the expense of microbial necromass. These organisms will mineralize some necromass-N, increase net N mineralization, and reduce the C:N ratio of substrate mineralized. Under severe conditions (addition of acid) the C:N ratio of substrate mineralized approaches that of the microbial biomass itself, suggesting that the biomass is the primary substrate mineralized. Microbial mortality is likely to be a significant factor affecting the supply of N in field situations, and should be included in any general model of soil N mineralization processes.  相似文献   

Effect of meclofenamic acid on the response of parasite-naive lambs and adult sheep to Ostertagia circumcincta     

E S Mitchell  Q A McKellar  J A Bogan 《Research in veterinary science》1990,49(2):166-170

Meclofenamic acid was used to inhibit prostaglandin synthesis in lambs challenged with Ostertagia circumcincta. It lowered the number of parasites which established in treated animals but not significantly. In treated animals plasma pepsinogen values were elevated at the time of parasite emergence but had dropped below the values achieved in control lambs towards the end of the experiment when parasites were at the adult, lumenal dwelling stage. Meclofenamic acid administered to adult immune ewes during challenge with third stage O circumcincta larvae did not significantly affect the establishment of the parasites, nor did it affect the rise in pepsinogen concentration associated with the challenge.  相似文献   

Acceleration and retardation of germination of some vegetable seeds resulting from treatment with copper fungicides     

J. M. Q. 《European journal of plant pathology / European Foundation for Plant Pathology》1947,53(6):190-190

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THE "SCIENCE MOBILIZATION BILL"     

Stewart JQ 《Science (New York, N.Y.)》1943,97(2526):486-487

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