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991.
Correlation of phenolic acid content of maize to resistance toSitophilus zeamais,the maize weevil,in CIMMYT'S collections 总被引:2,自引:0,他引:2
D. Classen J. T. Arnason J. A. Serratos J. D. H. Lambert C. Nozzolillo B. J. R. Philogéne 《Journal of chemical ecology》1990,16(2):301-315
The (E)-ferulic acid content of the grain of nine populations of land races of maize derived from CIMMYT's collections was found to be negatively correlated to susceptibility characteristics towards the maize weevilSitophilus zeamais. Correlation coefficients for six susceptibility parameters and (E)-ferulic acid content were significant and ranged from –0.58 to –0.79. A multiple regression analysis by the SAS forward procedure using the primary seed characteristics associated with susceptibility indicated that the ferulic acid content was the only significant factor in explaining variation in at least two susceptibility parameters: the Dobie index and adult preference. In 15 CIMMYT pools, correlations between four susceptibility parameters and (E)-ferulic acid content were also significant (–0.76 to –0.81). The results suggest that phenolic acid content is a leading indicator of grain resistance or susceptibility to insects and may represent a newly identified mechanism of resistance. 相似文献
992.
The basis of the examination is a clinical material of 14 years (from 1960 to 1973) of the urological clinic of the Medical University "Semmelweis", consisting of 160 patients with renal hypoplasia. In 116 of these cases a nephrectomy was performed. The average postoperative observation time was 7.8 years. By removal of the hypoplastic kidney the hypertension could be successfully influenced in 72% of the cases and in 16% moderately; in 12% of the patients the high blood pressure remained unchanged also after the intervention. On account of the recognition resulting from the examinations that by the hypoplastic kidney alone no increase of the blood pressure is caused, but the developmental anomaly forms a basis for the development of the hypertension, is emphasized that the early removal of this abnormally developed kidney is by all means indicated. 相似文献
993.
A short-term test to determine renal concentrating ability without any water deprivation has been described. It consists of osmolatity determinations in three onehour urine portions from spontaneous voidings following an intranasal application of 7 microng of the synthetic analogue of vasopressin-DDAVP per 0,5 m2 body surface. The values of maximal urine osmalatity over 900 mosm/Kg H2O following DDAVP are considered normal whereas values under 600 mosm are consistent with impaired renal function. If, however, the maximal urine osmolality is in the so called "uncertain range" i.e. from 600 to 900 mosm, it is advisable to perform in the same patients also the classical concentration test based on a prolonged dehydration (26 h). 相似文献
994.
995.
J-C. Hénaux G. Vernet R. Adde 《Journal of Infrared, Millimeter and Terahertz Waves》1983,4(4):665-680
The system temperature of a receiver using a Josephson junction as a self oscillator mixer has been measured in the range 0.6 to 2 THz. The experimental value TS=53000K (DSB) at 900 GHz is in good agreement with the calculated value. A TS~12 000 K is predicted with a 30 K i.f. amplifier Possible applications are related to fast frequency tunable receivers (over one octave) with limited spectral resolution. 相似文献
996.
997.
Much effort has gone into the recognition of the human right to water. Without doubt, this milestone influences governance and decision making processes at many scales so it is essential now to shift the discussion from the legal and conceptual framework to practice. Along this line, the article proposes a methodology for monitoring access to water in rural areas using the framework of this human right. The practicality of the approach is demonstrated by a case study carried out in Nicaragua. Different criteria of the right to water were included in surveys and structured interviews that were conducted in rural households and water committees, respectively. A discussion analyzes the advantages and challenges of using this framework. Finally, the approach provides elements for policy making that can be used by different stakeholders in the development and human rights sectors. 相似文献
998.
Renée Kidson Brent Haddad Hui Zheng Steven Kasower Robert Raucher 《Water Resources Management》2013,27(9):3209-3225
This paper considers the retail water provider’s purchasing decision of a portfolio of permanent contracts from wholesalers with multiple volatile water sources. We consider the reliability of two contract types: (1) fixed annual quantities, and (2) an inflow harvest function with storage. Our four-reservoir case in Sydney (Australia) has cross-correlated inflow data. To accommodate multi-reservoir cross-correlation we adapt Portfolio Theory from finance to lognormal reservoir inflows, re-framing traditional storage theory from the wholesaler’s optimal operating policy to the retailer’s optimal purchasing policy. We find that Reliability improves with access to a source pool (cf. fixed quantities from separate sources), demonstrating the ‘insurance effect’, and the portfolio that minimises lognormal variance also minimises harvest (and thus environmental impact). Reform direction in Australian (and other international) water markets is towards multi-provider vertical disintegration, which may reduce pool opportunities and negate the insurance effect. We consider diminishing reliability returns as reservoir harvesting increases, and conclude a retail portfolio of permanent contracts from reservoirs, plus short-term contracts from alternative sources (either independently or negatively cross-correlated) efficiently secures high reliability. The challenge in incomplete water markets remains in encouraging and sustaining supply diversification that may only be needed aperiodically during extreme droughts. 相似文献
999.
Electrochemical oxidation (decolorization/degradation) of blue and red commercial reactive azo dyes was carried out on boron-doped diamond (BDD) electrode. The effect of various quantities of FeSO(4) was investigated in the electro-Fenton reaction on BDD. Progress of dyes degradation during the electrolysis and electro-Fenton reaction was monitored by UV-visible absorption and by estimation of the chemical oxygen demand (COD). Direct electrolysis showed a limiting capacity for red and blue dye removal even at high current densities, e.g. maximum red color and COD removal were 70 and 20%, respectively at 30 mA cm(-2) after 300 min. Higher red and blue color removal efficiencies were achieved by electro-Fenton oxidation. Current density of 30 mA cm(-2) in the presence of 0.05 mmol/L of FeSO(4) resulted in the red color and COD removal of 98 and 96%, respectively. The optimum FeSO(4) concentration for the electro-Fenton reaction was determined to be 0.05 mmol/L. Instantaneous current efficiency (ICE) in the presence of FeSO(4) was almost three times higher than for experiments carried out without FeSO(4). 相似文献
1000.
Climate change is likely to influence the water cycle by changing the precipitation patterns, in some cases leading to increased occurrences of precipitation extremes. Urban landscapes are vulnerable to such changes due to the concentrated population and socio-economic values in cities. Feasible adaptation requires better flood risk quantification and assessment of appropriate adaptation actions in term of costs and benefits. This paper presents an economic assessment of three prevailing climate adaptation options for urban drainage design in a Danish case study, Odense. A risk-based evaluation framework is used to give detailed insights of the physical and economic feasibilities of each option. Estimation of marginal benefits of adaptation options are carried out through a step-by-step cost-benefit analysis. The results are aimed at providing important information for decision making on how best to adapt to urban pluvial flooding due to climate impacts in cities. 相似文献