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1.
Boulanger Yan Arseneault Dominique Boucher Yan Gauthier Sylvie Cyr Dominic Taylor Anthony R. Price David T. Dupuis Sébastien 《Landscape Ecology》2019,34(1):159-174
Landscape Ecology - Forest landscapes at the boreal–temperate ecotone have been extensively altered. Reducing the gap between current and presettlement forest conditions through... 相似文献
2.
Jessica Fry Juan Pérez Casanova Lynn Lush Andy Walsh Cyr Couturier 《Journal of aquatic animal health》2015,27(1):57-64
The direct exposure of fish eggs to ozonated water has generated interest as a means of ensuring pathogen-free eggs without the use of harsh chemicals. However, there are numerous knowledge gaps, including safe contact times, exposure levels, and potential long-term effects on aquaculture species in both freshwater and seawater. The effect of different ozone (O3) doses (0.5–1.0, 1.5–2.0, and 2.5–3.0 mg of O3/L for 90 s) on recently fertilized eggs of Atlantic Cod Gadus morhua and eyed eggs of Atlantic Salmon Salmo salar and Rainbow Trout Oncorhynchus mykiss was evaluated in comparison with the effects of two commercial disinfectants: Perosan (0.004 mg/L) and Ovadine (100 mg/L). The impact of ozone application was evaluated based on hatching success, larval nucleic acid concentration, larval growth, and survival. Overall, results indicated that ozonation of Atlantic Cod eggs at a dose less than 3.0 mg/L for 90 s produced no negative effect on the larvae up to 30 d posthatch. Furthermore, ozonation of Atlantic Salmon and Rainbow Trout eggs generated no negative effect on the larvae, based on monitoring until 85% yolk sac re-absorption (16 d posthatch).
Received May 6, 2014; accepted October 24, 2014 相似文献
3.
Context
Sustained timber harvesting conflicts with the long-term viability of boreal caribou (Rangifer tarandus caribou) populations. The spatial arrangement of harvest blocks in the landscape could mitigate the impact of logging on caribou populations. For the forest industry, however, these measures represent constraints that reduce the annual allowable cut (AAC).Objective
Estimate the long-term impacts of spatial constraints to harvesting, applied alone or in combination, on AAC and boreal caribou populations.Methods
We divided a 30,000 km2 region into 20 harvest block sizes varying from 50 to 1000 km2, and modeled the implementation of spatially explicit harvest schedule plans in combination with wildfire and caribou population dynamics. We then evaluated the probability of persistence of boreal caribou populations.Results
The probability of maintaining an AAC target declined with increasing target AAC, increasing size of operating area, and increasing adjacency constraints. In contrast, the probability of maintaining caribou populations declined with increasing AAC, decreasing size of operating areas, and decreasing adjacency constraints. An increase in operating area size from 50 to 300 km2 produced a considerable gain in AAC for all adjacency constraints.Conclusions
Because adjacency constraints led only to a small increase in the probability of maintaining caribou populations, we recommend adopting less constraining landscape management actions, such as a 70-year period between two consecutive harvests in the same ~300-km2 operating area.4.
The sensitivity and specificity of the indirect micro-enzyme-linked immunosorbent assay (ELISA) was compared with that of the rapid serum-plate test (RSPT) and the hemagglutination-inhibition test (HIT) in detecting antibodies to Mycoplasma gallisepticum (MG) and M. synoviae (MS). Membrane antigens of MG strain S6 and MS strain NEL 61800 were used. ELISA was performed with single MS and single MG antigens and a combined MS/MG antigen. The MS-ELISA was as sensitive as the MS-RSPT and more sensitive than and as specific as the MS-HIT in detecting antibodies to MS. The MG-ELISA was less sensitive than the MG-RSPT and slightly less sensitive than the MG-HIT in detecting antibodies to MG in chickens experimentally infected with MG R strain but more sensitive in detecting antibodies in chickens infected with MG F strain. MG-ELISA resulted in fewer cross-reactions than the MG-RSPT but more than the MG-HIT. The combined MG/MS-ELISA was as sensitive as the ELISA with its individual antigen components. No nonspecific reactions were observed with sera from MG/MS-free flocks. The combined MG/MS-ELISA was found to be a practical screening test for antibodies to both MS and MG. Further improvement of the sensitivity and the specificity of the MG antigen is desirable. 相似文献
5.
Scale-dependent determinants of heterogeneity in fire frequency in a coniferous boreal forest of eastern Canada 总被引：1，自引：0，他引：1
Despite the recognized importance of fire in North American boreal forests, the relative importance of stochastic and determinist
portions of intra-regional spatial variability in fire frequency is still poorly understood. The first objective of this study
is to identify sources of spatial variability in fire frequency in a landscape of eastern Quebec’s coniferous boreal forest.
Broad-scale environmental factors considered included latitude, longitude, human activities and belonging to a given bioclimatic
domain, whereas fine-scale factors included slope, position on the slope, aspect, elevation, surficial deposit and drainage.
The average distance to waterbodies was also considered as a potential intermediate-scale source of variability in fire frequency.
In order to assess these environmental factors’ potential influence, they were incorporated into a proportional hazard model,
a semi-parametric form of survival analysis. We also used a digital elevation model in order to evaluate the dominant aspect
within neighborhoods of varying sizes and successively incorporated these covariates into the proportional hazard model. We
found that longitude significantly affects fire frequency, suggesting a maritime influence on fire frequency in this coastal
landscape. We also found that position on the slope was related to fire frequency since hilltops and upperslopes were subject
to a lower fire frequency. Dominant aspect was also related to fire frequency, but only when characterized within a neighborhood
delimited by 4,000 to 10,000-m radii (5,027–31,416 ha). A 2–6-fold variation in fire frequency can be induced by geographic
and topographic contexts, suggesting a substantial intra-regional heterogeneity in disturbance regime with potential consequences
on forest dynamics and biodiversity patterns. Implications for forest management are also briefly discussed.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
6.
Lorelei A. Grecian G. Jay Parsons Patrick Dabinett Cyr Couturier 《Aquaculture International》2000,8(2-3):183-206
Hatchery-reared sea scallop (Placopecten magellanicus) spat weremonitored for growth and recovery in three experiments to determine themost suitable system for nursery culture. In Experiment I, four size classesof nursery-sized spat held at two depths from October to July exhibiteddeclining growth rates over the winter period and increased growth ratesin the spring. Overall, season, depth and initial size had a significantinfluence on the absolute and specific growth rates of scallops. Recovery,defined as number of scallops remaining after mortality and loss of spatthrough gear mesh, was influenced by season and initial size, but notdepth. Scallops in the 3.0 mm+ size class had higher growth rates andrecovery than those in the 1.4–1.6 mm, 1.7–1.9 mm and 2.0–2.9 mm sizeclasses. In Experiment II, two gear types containing similar size spat werecompared. Growth rates were significantly higher in 3.0 mm pearl nets thanin 3.0 mm collector bags, although recovery was similar between the twoequipment types. Experiment III, two stocking densities of nursery-sizedspat were compared in collector bags. Neither growth rate nor recoverywere significantly different for the two densities (2600 and 5200spat/collector bag) tested. Overall, these studies indicated that importantparameters for optimizing the growth and recovery of scallops in a farm-based nursery system include season, initial spat size, deployment depthand gear type. 相似文献
7.
T D Cyr F Matsui R W Sears N M Curran E G Lovering 《Journal of the Association of Official Analytical Chemists》1987,70(5):836-840
Liquid chromatographic (LC) methods have been developed for the determination of carbamazepine, the impurity 10,11-dihydrocarbamazepine, and related compounds in carbamazepine drug substance and tablets. The LC methods specify a 5 micron diol column and a mobile phase of acetonitrile-methanol-0.05% aqueous acetic acid (5 + 5 + 90). Iminodibenzyl and iminostilbene, starting materials for some routes of synthesis, elute late in the LC system; therefore, a thin-layer chromatographic method for their detection at the 0.05% level has been developed. Eight tablet and 13 raw material samples from several sources were examined. The impurities most frequently found were 10, 11-dihydrocarbamazepine and a compound identified as 10-bromocarbamazepine at levels up to 1.3 and 0.5%, respectively; minimum detectable amounts were about 0.01 and 0.03%, respectively. 相似文献
8.
Joe Luksovsky Thomas M. Craig Glenda M. Bingham Tracy Cyr David Forrest 《Journal of Equine Veterinary Science》2013
A study was undertaken at the Texas A&M Horse Center to evaluate and compare the effectiveness of three anthelmintics—ivermectin, fenbendazole, and a combination of ivermectin and pyrantel pamoate—on fecal egg count reductions of cyathostomes and Parascaris equorum in 30 naturally infected foals. The foals were randomized into three treatment groups, with individuals being rerandomized after each 8-week observation period. The treatments of ivermectin and fenbendazole were given at the manufacturer's recommended doses, and the pyrantel treatment was given at two times the manufacturer's recommended dose. Fecal egg counts were performed at the time of treatment and at 2-week intervals after treatment for a total of 8 weeks. Each foal received a total of three treatments during the course of the study. Fecal egg counts were performed by a modified McMaster's test, with a sensitivity of 25 eggs per gram of feces, and by the modified Wisconsin double centrifugal flotation technique, with a sensitivity of 0.2 eggs per gram of feces. Fecal egg reduction percentages were calculated. Analysis of the results showed that ivermectin, either used alone or with pyrantel, was a more effective anthelmintic for cyathostome (small strongyle) control than fenbendazole. Fenbendazole and pyrantel showed a higher initial reduction in Parascaris egg counts when compared with the ivermectin-only-treated group, but this difference lessened over time. The use of the combination treatment showed the best results for controlling both parasites, indicating that a combination of anthelmintics may be necessary to control parasites on some equine farms. 相似文献
9.
Ghislain Moussavou Dong Hoon Kwak Brice Wilfried Obiang-Obonou Cyr Abel Ogandaga Maranguy Sylvatrie-Danne Dinzouna-Boutamba Dae Hoon Lee Ordelia Gwenaelle Manvoudou Pissibanganga Kisung Ko Jae In Seo Young Kug Choo 《Marine drugs》2014,12(9):4898-4911
Seafoods and seaweeds represent some of the most important reservoirs of new therapeutic compounds for humans. Seaweed has been shown to have several biological activities, including anticancer activity. This review focuses on colorectal and breast cancers, which are major causes of cancer-related mortality in men and women. It also describes various compounds extracted from a range of seaweeds that have been shown to eradicate or slow the progression of cancer. Fucoidan extracted from the brown algae Fucus spp. has shown activity against both colorectal and breast cancers. Furthermore, we review the mechanisms through which these compounds can induce apoptosis in vitro and in vivo. By considering the ability of compounds present in seaweeds to act against colorectal and breast cancers, this review highlights the potential use of seaweeds as anticancer agents. 相似文献
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