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To characterize the biochemical differences in paraquat-resistant and -susceptible biotypes of Erigeron canadensis L. collected from Korea, we investigated the constitutive levels of various antioxidants such as antioxidant enzymes and low molecular weight antioxidants in leaves, as well as after paraquat treatment. The activities of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase were higher in the paraquat-resistant biotype than in the paraquat-susceptible biotype. Reduced ascorbic acid content was higher in the resistant biotype, but the content of reduced glutathione was higher in the susceptible biotype. These results indicate that one of the paraquat-resistant mechanisms in E. canadensis in the present study might be related to protecting the activities of antioxidant enzymes, such as superoxide dismutase, peroxidase ascorbate peroxidase, and catalase, as well as the contents of low molecular weight antioxidants such as ascorbate and glutathione.  相似文献   
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在马鞍山市马鞍山林场,对松材线虫病(Bursaphelenchus xylophilus)的传媒昆虫松墨天牛(Monochamus alternatus)的病原微生物进行调查,结果鉴定了8种真菌和1种细菌.对松墨天牛幼虫的致病率测定显示不同的微生物种类和同一种白僵菌(Beauveria bassiana)的不同菌株均有显著差异.白僵菌的高毒力菌株营养生长无明显差异,而产孢量有明显差异.通过测定,白僵菌菌株226可能是优良菌株,对生物防治松黑天牛方面有潜在的实用价值.  相似文献   
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BO-KYU  HWANG  HYEON-OK  SHIN 《Fisheries Science》2003,69(2):300-307
ABSTRACT:   A mooring-type underwater positioning system (UPS) to measurethe bag-net movements in a set-net by acoustic telemetry techniqueswith five transponders was reconstructed. The field experimentswere conducted in Jaran Bay, Kosung, Korea on 6 October 2000 (neaptide) and 28 November 2000 (spring tide). The average UPS fixingerrors of x -axis, y -axis and z -axis were less than0.6 m, 0.8 m and 1.2 m, respectively.The longitudinal movement range, the latitudinal range and the verticalrange of the bag-net at the neap tide were 3.2 m, 3.4 mand 2.1 m, respectively. At the spring tide, these rangeswere 7.8 m, 7.8 m and 5.0 m, respectively.It was confirmed that the UPS system could be used for measuringa part of the bag-net movement.  相似文献   
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Proteus spp. are widely recognized as opportunistic pathogens causing urinary tract and septic infections in humans and animals. The aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance genes and mutations in the quinolone resistance determining region in association with the detection of quinolone susceptibility of 24 strains of pet turtle-borne Proteus spp. Susceptibility of 4 antimicrobials including nalidixic acid, ciprofloxacin, ofloxacin, and levofloxacin was examined by disk diffusion and minimum inhibitory concentration test. Six isolates were resistant to nalidixic acid showing either intermediate resistance or resistance to other quinolones. All nalidixic acid, resistant isolates harbored mutations in gyrB (N440T/A401G/Q411S). Two of the isolates had both gyrA (S83I) and parC (S80I) mutations. Twenty-one isolates were positive for the presence of plasmid-mediated quinolone resistance genes; the qnrD gene had the highest prevalence with 19 (79.2%), while qnrS, qnrA, qnrB, and aac(6′), Ib-cr genes were present in 9 (37.5%), 2 (8.3%), 1 (4.2%), and 11 (45.8%) isolates, respectively. These results suggest that pet turtle-associated Proteus spp. should be considered a potential source of antimicrobial resistance determinants.  相似文献   
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Two feeding experiments were conducted to investigate the effects of dietary inclusion of different plant ingredients on growth and body composition of juvenile sea cucumber. In the first experiment, three replicate groups of the sea cucumber (average weight of 1.5 ± 0.05 g) were fed one of the seven experimental diets containing Sargassum thunbergii (CON), Undaria (UND), Laminaria (LAM), Brassica oleracea L. var. capitata (BRA), fermented soybean (FSB), distillers dried grain (DDG) and rice straw powder (RIC) for 10 weeks. After the feeding trial, survival was not significantly different among the dietary treatments. Specific growth rate (SGR) of sea cucumber fed the FSB diet (0.73) was significantly higher than that of sea cucumber fed the other diets (P < 0.05), except for the DDG diet (0.64). The lowest SGR was observed in sea cucumber fed the CON diet (0.14). Based on the result of the first experiment, the second experiment was conducted to determine the proper level of dietary DDG for growth of juvenile sea cucumber. Three replicate groups of sea cucumber (average weight of 1.6 ± 0.02 g) were fed one of the five experimental diets containing different levels (g kg?1) of DDG (DDG0, DDG10, DDG20, DDG30 and DDG40) for 12 weeks. Survival was not significantly different among the treatments (P > 0.05). The best SGR was obtained in sea cucumber fed the DDG10 diet (10.1) and the value of sea cucumber fed the DDG40 diet (5.6) was the lowest (P < 0.05). The SGR of sea cucumber fed the DDG10 diet did not differ from that of sea cucumber fed the DDG20 diet (P > 0.05). Moisture, crude protein, crude lipid and ash contents of whole body in sea cucumber among the dietary treatments (P > 0.05) did not differ significantly at both experiments. Results of two feeding trial suggest that dietary inclusion with 100 g kg?1 FSB or 100–200 g kg?1 DDG may improve growth of juvenile sea cucumber, and especially DDG could be used as a good ingredient for the low‐cost feed formulation.  相似文献   
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The effects of feeding glucose during the 5 days before parturition on litter performance and on glucose concentration in sows were studied. At day 100 of gestation, 130 multiparous sows were assigned to the treatments. Late gestating sows were fed 0 g, 150 g, 250 g, 350 g and 450 g of glucose a day, respectively. During lactation, all sows were given free access to the same lactation diet (without glucose). One day before parturition, blood samples were collected from 30 sows (6 sows per treatment) at 10 before and 20, 40, 60 and 80 min after the meal. The supply of additional dietary glucose increased piglet birth weight ( P  < 0.05). Feed intake in week 1 and week 1–4 of lactation was greatest in sows fed the 0% glucose diet, least by sows fed the 18% glucose diet, and intermediate by sows fed the 6, 10, 14% glucose diets ( P  < 0.05). Basal glucose concentration and time of maximum glucose concentration after glucose intake were not affected by dietary treatment in the last 5 days of gestation. The sows fed the 14 and 18% glucose diets had greater maximum increase in glucose concentration than sows fed diet without glucose ( P  < 0.05). In conclusion, feeding glucose to sows during 5 days before parturition increased birth weight of live-born piglet and decreased sows feed intake during lactation, but did not affect the performance of sows and piglets.  相似文献   
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JUN  OHTOMI  TAKUYA  TASHIRO  SHIN  ATSUCHI  NATSUKI  KOHNO 《Fisheries Science》2003,69(3):505-519
ABSTRACT:   The Yatsushiro Sea and Shibushi Bay are, respectively, located on the western and south-eastern coast of Kyushu, southern Japan. The Yatsushiro Sea is a shallow semi-enclosed inland sea, whereas Shibushi Bay is an open-type bay with a deep and wide mouth facing the open sea. The size at sexual maturity and spatiotemporal patterns of reproduction of the kuruma prawn Marsupenaeus japonicus (Decapoda, Penaeidae) were examined and compared between these two regions. In the Yatsushiro Sea, the size at sexual maturity was estimated to be 131 mm body length. However, the estimated size at sexual maturity was considerably larger (154 mm) in Shibushi Bay. The spawning season of M. japonicus was estimated to continue from April to September in the Yatsushiro Sea, whereas it was estimated to be longer in Shibushi Bay, from March to November. It is believed that the warm water temperature due to the strong effect of the Kuroshio Current prolonged the spawning season of M. japonicus in Shibushi Bay. The spawning grounds were estimated to be in areas deeper than 10 m in the Yatsushiro Sea and deeper than 20 m in Shibushi Bay. In Shibushi Bay, body size distribution of mature females was considered to be less affected by water depth in comparison with the Yatsushiro Sea, although older mature females larger than 200 mm body length also spawned outside of the bay.  相似文献   
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