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Cytochromes: chemical and structural aspects 总被引：1，自引：0，他引：1
B Chance 《Science (New York, N.Y.)》1968,159(815):654-658
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In spite of the good results obtained in the control of Ceratitis under field conditions on the Italian islands of Capri and Procida, in Nicaragua and in the Spanish Murcia area, several problems connected with the sterile male technique still have to be solved. Mass rearing of the insects must be improved. Perhaps, total sterility of the males is not required and the necessary dose of irradiation must be studied in relation to its effect on their competitiveness in the field. In checking the efficacy of field operations the recapture of marked individuals will have to be supplemented or gradually replaced by the time-consuming assessment of egg-hatching and fruit-damage. Studies of the influence of environmental factors on population densities must be intensified. 相似文献
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Effect of repeated exposure to AQUI‐S® on the viability and growth of Neoparamoeba perurans 
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下载免费PDF全文 There have been recent efforts amongst immunologists to develop approaches for following individual fish during challenges with viral and bacterial pathogens. This study contributes to assessing the feasibility of using such approaches to study amoebic gill disease (AGD). Neoparamoeba perurans, agent of AGD, has been responsible for widespread economic and fish loss in salmonid aquaculture. With the emergence of AGD in Europe, research into infection dynamics and host response has increased. This study investigated the effect of repeat exposure to anaesthesia, a necessary requirement when following disease progression in individual fish, on N. perurans. In vitro cultures of N. perurans were exposed every 4 days over a 28‐day period to AQUI‐S® (isoeugenol), a popular anaesthetic choice for AGD challenges, at a concentration and duration required to sedate post‐smolt salmonids. Population growth was measured by sequential counts of amoeba over the period, while viability of non‐attached amoeba in the culture was assessed with a vital stain. AQUI‐S® was found to be a suitable choice for in vivo ectoparasitic challenges with N. perurans during which repetitive anaesthesia is required for analysis of disease progression. 相似文献
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Zucchini squash (Cucurbita pepo L. cv. Green Magic) plants were grown hydroponically with nitrate (NO3):ammonium (NH4) ratio of 3:1 until the onset of flowering when the plants were assigned to four NO3:NH4 ratio (1:0, 1:1, 1:3, or 3:1) treatments. Changing the original nitrogen (N) form ratio significantly affected plant growth, fruit yield, nutrient element, and water uptake. Growth of plants was better when NO3‐N (1:0) was the sole form of N than when NH4‐N was part of the N treatment. Fruit yields for plants fertilized with 1:0 or 1:3 N‐form ratio were double those of plants grown continuously with 3:1 N ratio. The largest leaf area and plant water use were obtained with 1:0 N ratio treatment Total uptake of calcium (Ca), magnesium (Mg), and potassium (K) decreased with increasing NH4‐N proportion in the nutrient solution which suggest NH4‐N was competing with these cations for uptake. The results also demonstrated that growers may increase fruit yield by using a predominantly NO3‐N source fertilizer through the vegetative growth stage and by shifting the NO3:NH4 ratio during the reproductive phase. 相似文献
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The hydroperoxyl radical (HO(2)) plays a key role in stratospheric chemistry through the HOx catalytic cycle of ozone destruction. Earlier measurements of stratospheric HO(2) have given mixed results; some measured mixing ratios greatly exceed theoretical predictions. Measurements of HO(2) have now been made with a balloon-borne farinfrared spectrometer. The measured daytime profile is in excellent agreement with theory up to 40 kilometers; above this level the measurements exceed theory by 30 percent, perhaps because of underprediction of ozone at these altitudes. The nighttime HO(2) profile is strongly depressed with respect to the daytime profile, in general agreement with theory. 相似文献
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Tranel PJ Riggins CW Bell MS Hager AG 《Journal of agricultural and food chemistry》2011,59(11):5808-5812
Amaranthus tuberculatus is a major weed of crop fields in the midwestern United States. Making this weed particularly problematic to manage is its demonstrated ability to evolve resistance to herbicides. Herbicides to which A. tuberculatus has evolved resistance are photosystem II inhibitors, acetolactate synthase inhibitors, protoporphyrinogen oxidase inhibitors, and glyphosate. Many populations of A. tuberculatus contain more than one of these resistances, severely limiting the options for effective herbicide control. A survey of multiple-herbicide resistance in A. tuberculatus revealed that all populations resistant to glyphosate contained resistance to acetolactate synthase inhibitors, and 40% contained resistance to protoporphyrinogen oxidase inhibitors. The occurrences of multiple-herbicide resistances in A. tuberculatus illustrate the need for continued herbicide discovery efforts and/or the development of new strategies for weed management. 相似文献