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排序方式： 共有216条查询结果，搜索用时 15 毫秒
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MAXIME LAVOIE PIERRE-YVES COLLIN FLORENT LEMIEUX HÉLÈNE JOLICOEUR PIERRE CANAC-MARQUIS SERGE LARIVIÈRE 《The Journal of wildlife management》2009,73(6):870-875
ABSTRACT In Quebec, Canada, harvest of bobcats (Lynx rufus) started to decline in 1985 and by 1991, harvest seasons were closed due to concerns of a perceived population decline. Since the closing of harvest season in 1991, the average temperature has increased, snow quantity has decreased, and important changes in agriculture and forest management have occurred. In light of changing conditions, the situation of Quebec bobcats needed reassessment. Thus, we analyzed harvest data to clarify the current status of bobcat populations in Quebec. From 1980 to 1991, bobcat harvest in Quebec was strongly correlated with bobcat harvest in Maine (USA), Nova Scotia (Canada), Ontario (Canada), and Vermont (USA). Extrapolations of harvest in Quebec relative to harvest in Maine, Ontario, Vermont, and Nova Scotia suggested an increase in number of bobcats after 1991. Mass of male and female bobcats before 1991 was less than mass of animals captured after 1991. Percentage of juveniles in the reported harvest before 1991 was higher than after 1991. However, percentage of males and litter sizes in the harvest did not differ before and after 1991. The geographic distribution of bobcats captured has gradually expanded after the closure of the harvest season. Our findings suggest that bobcat populations in Quebec have recovered from the 1985–1991 decline, and that the harvest season for this species could resume. This study also illustrates how managers can rely on data from neighboring jurisdiction to manage species when local harvest data is unavailable. 相似文献
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Comparative characterization of laboratory-made selective nutrient media for Salmonella accumulation
Zakharova NE Sukhanova SM Beliaeva GA 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2004,(5):101-103
In this work the results of the trial of three selective nutrient media for Salmonella accumulation, viz. Leifson's selenite broth produced by the Research and Manufacturing Amalgamation (RMA) Nutrient Media, tetrarathionate broth (Müller's medium), laboratory-prepared, and newly developed MA-broth produced by the RMA Nutrient Media, are presented. The results of 6- and 24-hour incubation in these selective media was evaluated. As found in this study, the laboratory-prepared medium was most effective for the accumulation of salmonellae (S. paratyphi, S. typhi, S. gallinarum). With respect to the possible concomitant microflora (Escherichia coli and shigellae), the inhibiting properties of MA-broth were superior to those of Leifson's medium, but inferior to those of Müller's medium. 相似文献
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A kinetic model of the cytochrome bf complex was developed on the assumption that the Q-cycle operates. The bf complex was considered as a membrane enzyme catalyzing the electron transfer from plastoquinol to plastocyanine, which is coupled with proton translocation from the chloroplast stroma to the thylakoid lumen. The dependence of the electron transfer rates on the value of the transmembrane electric potential was taken into account. The model was applied to describe the experimental data on the flash-induced turnover of cytochromes b, plastocyanine, and the kinetics of proton deposition in the thylakoid lumen. The estimation of model parameters was performed. 相似文献
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The use of the photochemical reflectance index (PRI) as a promising proxy of light use efficiency (LUE) has been extensively studied, and some issues have been identified, notably the sensitivity of PRI to leaf pigment composition and the variability in PRI response to LUE because of stress. In this study, we introduce a method that enables us to track the short‐term PRI response to LUE changes because of photosynthetically active radiation (PAR) changes. The analysis of these short‐term relationships between PRI and LUE throughout the growing season in two species (Quercus robur L. and Fagus sylvatica L.) under two different soil water statuses showed a clear change in PRI response to LUE, which is related to leaf pigment content. The use of an estimated or approximated PRI0, defined as the PRI of perfectly dark‐adapted leaves, allowed us to separate the PRI variability due to leaf pigment content changes and the physiologically related PRI variability over both daily (PAR‐related) and seasonal (soil water content‐related) scales. The corrected PRI obtained by subtracting PRI0 from the PRI measurements showed a good correlation with the LUE over both of the species, soil water statuses and over the entire growing season. 相似文献
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The respiration of subline Leb-25 cells, resistant to ethidium bromide (EB, 25 g/ml), is 2.5 times slower than the respiration of parental L cells of mouse fibroblasts. The EB resistant cells have a normal level of ATP. Disturbances of mitochondrial functions can be observed such as a defect of the succinate dehydrogenase complex and the uncoupling of respiration and oxidative phosphorylation in mitochondria of Leb-25 cells. 相似文献
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N S Beliaeva 《Parazitologiia》1975,9(4):352-353
Results of the experiments have shown that the development of Dermacentor silvarum from egg to imago varied from 44 to 46 days at 28 C and redundant humidity and from 50 to 52 days at 25 degrees C. The thermic threshold of larval development lies within a range of 8.6 degrees C, that of nymphs-9.7 degrees C. A sum of effective temperatures required for larval development averaged 123.5 degrees C, for nymphs-225 degrees C and for the whole ontogenesis-from 570 to 690 degrees C. In the north of the distribution area of D. silvarum this species seems to occur only in those localities, where a sum of effective temperatures is higher than 10 C and makes not less than 570 degrees C. 相似文献
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