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1.
Traditional forest economics deals with regularly-ordered activities.For many reasons, however, choices must often be made amongconflicting operational priorities. In these circumstances,maximizing net discounted revenue per hectare does not maximizeglobal profit. Priorities for action should be chosen in orderof urgency index ratio, defined as the cost of delaying an operationdivided by the units of limited resource needed to undertakethe operation. Forest managers tend to use informal and sometimesconflicting rules to assign priorities among uses of limitedresources. These priorities often differ from those indicatedby urgency index ratio. Urgency index ratio can be determinedby simple calculations based on readily-available data. Theconcept can be extended to include multiple constraints. 相似文献
2.
Strategies for control of seed-borne Alternaria dauci (leaf blight) of carrots in priming and process engineering systems 总被引:1,自引:0,他引:1
R. B. MAUDE R. L. K. DREW D. GRAY G. M. PETCH W. BUJALSKI A. W. NIENOW 《Plant pathology》1992,41(2):204-214
Laboratory and glasshouse experiments demonstrated that priming of carrot seeds infected with Alternaria dauci did not affect the rate of transmission of the pathogen. Iprodione applied as a dust to unprimed, infected seeds at 5 ga.i. per kg seed effectively reduced disease transmission. Iprodione (0.1% a.i.) or thiram (0.1% a.i.) added in polyethylene glycol (PEG; filter paper or bubble-column priming systems) only partially reduced infection. Further dusting of the primed and dried seeds with iprodione, or alternatively application of that fungicide in a polymer film coat as the final stage in the process engineering of carrot seeds, was necessary to achieve complete control. The addition of thiram in the priming fluid, followed by an application of iprodione to the primed and dried seeds, improved the emergence and yield of carrots in the field. 相似文献
3.
1. Oxidation of meat and membrane from broilers fed on a diet containing 500 mg/kg rosemary and sage extracts was compared to meat and membrane oxidation from broilers receiving a control diet (not enriched with antioxidants) and a diet enriched in alpha-tocopheryl acetate (200 mg/kg). 2. After 9 d of refrigerated storage, thiobarbituric acid reactive substances of white meat from broilers fed on the control and the alpha-tocopheryl acetate-enriched diets were 0.51 and 0.25 mg malonaldehyde/kg meat, respectively. Values for meat from broilers fed on the diets containing the rosemary and sage extracts were in the range 0.30 to 0.35 mg malonaldehyde/kg meat, significantly lower than those from birds fed on the control diet. A similar trend was observed in the dark meat but differences were not significant at 9 d of storage. Similar trends were observed in raw samples stored at- 20C for up to 4 months and in samples cooked at 70C and kept stored under refrigeration for up to 4 d. 3. The meat from broilers fed on the diet containing spice extracts had smaller concentrations of total cholesterol oxidation products (COPS) than meat from the control group (P<0.05). Supplemental alpha-tocopheryl acetate reduced the COPS concentrations to a greater extent than did spice extracts (P<0.05). 4. A similar trend was observed in microsomal fraction isolates, in which the rate of metmyoglobin/hydrogen peroxide-catalysed lipid peroxidation was lower in animals receiving spice extracts than in those fed on the basal diet. 相似文献
4.
Abstract Two methods of otolith increment analysis were used to describe spatial, temporal and gender variation in growth of sand whiting, Sillago ciliata (Cuvier), in four south‐east Australian estuaries. Mean annual standardised otolith increment widths were used as indices of individual lifetime growth rates, while raw otolith increment widths were used to describe variation in growth throughout the life of S. ciliata. Temporal variation in growth was observed at an annual scale, while spatial variation in growth was observed between estuaries. Growth rates increased significantly with decreasing latitude and greater mean sea surface temperatures. A divergence in growth rates between sexes was detected, with females growing faster than males after sexual maturity. This study highlights how otolith increment analyses can: (1) be used to analyse temporal trends in growth from a single sample and (2) provide insight into juvenile growth when samples have an absence of undersized fish. 相似文献
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