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61.
Abstract: In recent years, international education has become a source of considerable political, academic and media debate in New Zealand. This is nowhere more the case than with regards to Auckland, the New Zealand city that has hosted the greatest number of international students. This paper focuses on the media debates around international students in Auckland with particular emphasis on the representations of the largest group of international students, those who originate from countries within the North‐East Asian region. The media representations of these students have fixed a diverse group of individuals within a singular racial identity that is known by stereotypical economic, cultural and social characteristics. As a result, these representations have further problematised the interaction between international students and the host population in Auckland while simultaneously implicating a cohort of young New Zealand citizens and permanent residents who are of similar descent within the same discourses. This process of othering the Asian student, regardless of citizenship, has consequences not simply for the practice of exporting education in this city but also for the future of a multicultural Auckland and New Zealand.  相似文献   
62.
Growth trials were conducted outdoors in the UK to determine the yield, yield components and plant architectural differences between determinate and indeterminate Phaseolus vulgaris bean plants. F3 lines derived from crosses between ‘Prelude’, a determinate cultivar and ‘V8’, an indeterminate landrace, were grown together with the parents and ‘Carioca’, an indeterminate landrace from Brazil. Data were recorded on flowering date, number of nodes on main stem at flowering, plant height at maturity, number of pods/plant, number of seeds/pod, number of seeds/plant, 100-seed weight, seed mass/plant, percentages of diseased and healthy seeds/plant. Determinate F3 lines had significantly lower (P < 0.05) seed mass/plant, fewer pods/plant, fewer seeds/pod, fewer seeds/plant, lower harvest index, shorter stems, earlier date of flowering, fewer nodes at flowering and fewer healthy seeds/plant than indeterminate F3 lines. However, determinate genotypes had significantly larger (P < 0.05) pods to accommodate their larger seeds compared with indeterminate lines. A similar situation was found when the yield and yield components of ‘V8’, ‘Prelude’ and ‘Carioca’ were evaluated; the highest seed mass/plant was given by ‘V8’ and the lowest by ‘Prelude’. Furthermore, some indeterminate genotypes with Type IV growth habit yielded significantly higher (P < 0.05) than the high-yielding parent, ‘V8’, indicating a positive influence on seed yield by crossing different genotypes.  相似文献   
63.
Understanding the interactions between soil and the organisms that are conducive to decreasing sediment runoff is a great concern on high-elevation ski trails. Intense rainfalls on steep slopes combined with soil formed on gypsum result in recurrent erosion. This study was conducted in the northern French Alps to determine the abilities of species: (1) to make mounds and (2) to trap sediment and thereby to control erosion at the slope scale. We also investigated relevant above-ground plant characteristics related to those abilities. Sediment runoff or deposition was investigated at small and large spatial scales. We assessed whether hoof prints in soil reflect sediment runoff at the slope scale by trapping sediment. Populations of plants growing on two slope angles (25° and 35°) and three vegetation cover densities (15%, 35%, 60%) were surveyed. An experiment was also conducted to measure the sediment deposit upslope of target species and over three months during the autumn. Small mounds were found upslope of the plant and sediment deposit measurements showed that they resulted from a sedimentation process. Nevertheless the species differed in their capacity to make mounds. Sesleria caerulea and Festuca alpina had the highest amount of sediment deposition over the experimental period. Among the plant characteristics, plant length was positively correlated with mound area, while the roundness index of the canopy was negatively correlated with mound height. Mound formation was also positively related to the number of tillers or shoots. Sediment accumulation in cow hoof prints was linked to runoff that occurred at the slope scale. Low deposition in hoof prints means low sediment runoff or a large deposition on mounds, due to the increase in vegetation cover. All the findings stressed that understanding the processes in action at larger scales requires studying processes at smaller scales.  相似文献   
64.
A sensitive, highly selective liquid chromatographic (LC) method is described which uses electrochemical (EC) reduction of the analyte in the determinative step. The method is capable of determining xanthomegnin in mixed animal feeds and grains at levels ranging from 15 to 1200 ng/g. The method can detect as little as 0.5 ng xanthomegnin injected on the LC column. Xanthomegnin is extracted with chloroform and 0.1M phosphoric acid. An aliquot of the crude extract is purified by silica gel column chromatography using a Sep-Pak silica gel cartridge. A novel feature of the method is that xanthomegnin is "backed off" the column by reversing the flow of the eluant through the column. LC is then used to separate xanthomegnin from other interfering substances. Xanthomegnin is detected by EC reduction at -0.16 V. Recoveries of xanthomegnin added to samples at levels ranging from 15 to 1200 ng/g averaged 79% with a coefficient of variation of 7.9%. Results also demonstrate that this LC system can separate the related metabolites viomellein and rubrosulphin from each other and from xanthomegnin and that the same EC detection system can be used to detect these metabolites.  相似文献   
65.
Wong  J. W. C.  Lai  K. M.  Su  D. S.  Fang  M. 《Water, air, and soil pollution》2001,128(3-4):339-353
The use of sewage sludge on agriculture provides an alternativefor sewage sludge disposal. Therefore, it was the aim of thepresent study to evaluate the feasibility of using a domestic(Tai Po sludge) and an industrial (Yuen Long sludge) sewagesludge produced in Hong Kong for the growth of vegetable crops.The acidic loamy soil with or without lime treatment was amendedseparately with each sludge at application rates of 0, 5, 10, 25and 50% (v/v) for the growth of a common local vegetable crop,Brassica chinensis. The plant available metal contents, asindicated by the DTPA extraction, increased with an increase insludge amendment, but decreased with lime amendment at eachsludge application rate due to the reduced metal availabilityat a higher pH. Sludge amendment enhanced the dry weight yieldof B. chinensis and the increase was more obvious for thesoil with lime treatment. The industrial sludge caused a loweryield than that of the domestic sludge amendment and asignificant reduction in yield at high application rates of YuenLong sludge was also noted. Tissue heavy metal contents, exceptfor Fe, increased as the sludge amendment rate increased whileplant grown in Yuen Long sludge amended soil contained higher Crand Zn contents at each sludge application rate. Liming the soilreduced the heavy metal contents in the plant tissues, exceptfor Fe, which were all below the allowable levels for vegetablecrops. The present experiment demonstrates that liming wasimportant in facilitating the growth of B. chinensis in sludge amended soil. The optimal sludge amendment rate for thesoil with lime amendment was 25% Tai Po sludge and 10% YuenLong sludge, while for the soil without lime amendment was 10% and5%, respectively.  相似文献   
66.
67.
Leachates from two landfills, namely Junk Bay (JB) and Gin Drinkers' Bay (GDB), were assessed for their acute toxicity using four green algal species, Chlorella pyrenoidosa, C. vulgaris, Scenedesmus sp. and Dunaliella tertiolecta. JB leachate was more toxic to the four algal species tested than leachate from GDB landfill. The growth rates of all four species in 50% JB leachate, and two species (C. vulgaris and D. tertiolecta) in 50% GDB leachate were significantly lower (P<0.05) than those in the control (Bristol Medium only). Values of 96h-EC50 of JB leachate for all four species were lower than those of GDB. The high contents of ammoniacal-nitrogen and organic compounds (such as volatile fatty acids) seemed to be the factors governing the toxicity of leachate on algae. There were differential sensitivities to leachate exhibited by the tested algal species. Susceptibility to leachates in terms of cell number were in the ascending order of C. pyrenoidosa, Scenedesmus sp., C. vulgaris and D. tertiolecta.  相似文献   
68.
The crude methanol extracts of the root barks of Turraea wakefieldii and Turraea floribunda were found to show mosquito larvicidal activity against third-instar larvae of Anopheles gambiae sensu stricto. Four new limonoids comprising a vilasininoid 1 and three havanensinoids 2-4 were isolated from the chloroform fractions of the methanol extracts of T. wakefieldii and T. floribunda, respectively. The structures of the compounds were elucidated by NMR spectroscopy. Compounds 1, 2, and 4 had LD50 values of 7.1, 4.0, and 3.6 ppm, respectively, and were more potent than azadirachtin, which had an LD50 value of 57.1 ppm when tested against larvae of A. gambiae.  相似文献   
69.
This paper reports research that attempts to rehabilitate toxic Pb/Zn mine tailings, in Guangdong, China, to achieve a healthy functional soil that supports sustainable vegetation. We studied the effects of the earthworm Pheretima guillelmi on the growth of a woody legume Leucaena leucocephala on Pb/Zn mine tailings diluted with varying amounts of mineral soil in pot experiments. L. leucocephala grew successfully on tailings with a 25% (w/w) soil amendment, but P. guillelmi only survived and actively burrowed with a 50% soil amendment. The presence of earthworms improved the yield of plants by 10-30%. Whilst earthworms marginally increased available N and P in soil, they increased uptake of phosphorus (by about 10%) to above-ground plant tissues. Six-month-old plants were more sensitive than 10-month plants to metal stress. P. guillelmi increased bioavailable metal concentrations in the amended spoils, accompanied by a direct increase of metal uptake by the plants. Increased metal uptake by plants was largely due to the higher dry matter production stimulated by earthworm activity, but this increased the rate of metal uptake into plants from spoil by at least 16% and as much as 53%. These results demonstrate that we should broaden the ecological context of phytoremediation by considering the plant-soil-animal interactions that influence metal mobility.  相似文献   
70.
Three triterpenoids, betulinic acid, oleanolic acid, and ursolic acid, were isolated as their methyl esters (treatment with diazomethane) from diethyl ether extracts of almond hulls (Nonpareil variety) using flash chromatography and preparative high-performance liquid chromatography. The triterpenoids, which comprised approximately 1% of the hulls, were characterized using chromatographic and spectroscopic methods. These studies demonstrate that almond hulls are a rich source of these triterpenoids, which have reported anti-inflammatory, anti-HIV, and anti-cancer activities.  相似文献   
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