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排序方式: 共有338条查询结果,搜索用时 15 毫秒
331.
332.
Seismic evidence for olivine phase changes at the 410- and 660-kilometer discontinuities 总被引:1,自引:0,他引:1
The view that the seismic discontinuities bounding the mantle transition zone at 410- and 660-kilometer depths are caused by isochemical phase transformations of the olivine structure is debated. Combining converted-wave measurements in East Asia and Australia with seismic velocities from regional tomography studies, we observe a correlation of the thickness of, and wavespeed variations within, the transition zone that is consistent with olivine structural transformations. Moreover, the seismologically inferred Clapeyron slopes are in agreement with the mineralogical Clapeyron slopes of the (Mg,Fe)2SiO4 spinel and postspinel transformations. 相似文献
333.
(−)-Untenospongin B isolated from the marine sponge Hippospongia communis has been tested for its antimicrobial activity against bacteria and human pathogenic fungi using agar disk method and was found to possess a broad and strong activity toward the test organisms. Its antifungal activity was further characterized by determination of the minimum inhibitory concentration (MIC) against five fungal species using broth microdilution method. 相似文献
334.
Helena Gaspar Sonia Savluchinske Feio Ana Isabel Rodrigues Rob Van Soest 《Marine drugs》2004,2(1):8-13
The antifungal activity of the sesquiterpenoids (+)-curcuphenol and (+)- curcudiol isolated from the Caribbean sponge Didiscus oxeata was evaluated against several filamentous fungi. 相似文献
335.
336.
The impacts of roads and other infrastructure on mammal and bird populations: A meta-analysis 总被引:3,自引:0,他引:3
Biodiversity is being lost at an increased rate as a result of human activities. One of the major threats to biodiversity is infrastructural development. We used meta-analyses to study the effects of infrastructure proximity on mammal and bird populations. Data were gathered from 49 studies on 234 mammal and bird species. The main response by mammals and birds in the vicinity of infrastructure was either avoidance or a reduced population density. The mean species abundance, relative to non-disturbed distances (MSA), was used as the effect size measure. The impact of infrastructure distance on MSA was studied using meta-analyses. Possible sources of heterogeneity in the results of the meta-analysis were explored with meta-regression.Mammal and bird population densities declined with their proximity to infrastructure. The effect of infrastructure on bird populations extended over distances up to about 1 km, and for mammal populations up to about 5 km. Mammals and birds seemed to avoid infrastructure in open areas over larger distances compared to forested areas, which could be related to the reduced visibility of the infrastructure in forested areas. We did not find a significant effect of traffic intensity on the MSA of birds. Species varied in their response to infrastructure. Raptors were found to be more abundant in the proximity of infrastructure whereas other bird taxa tended to avoid it. Abundances were affected at variable distances from infrastructure: within a few meters for small-sized mammals and up to several hundred meters for large-sized mammals.Our findings show the importance of minimizing infrastructure development for wildlife conservation in relatively undisturbed areas. By combining actual species distributions with the effect distance functions we developed, regions sensitive to infrastructure development may be identified. Additionally, the effect distance functions can be used in models in support of decision making on infrastructure planning. 相似文献
337.
Backues K Clyde V Denver M Fiorello C Hilsenroth R Lamberski N Larson S Meehan T Murray M Ramer J Ramsay E Suedmeyer K Whiteside D;Executive Committee American Association of Zoo Veterinarians 《Journal of zoo and wildlife medicine》2011,42(1):176-192
These guidelines for veterinary medical care and veterinary hospitals are written to conform with the requirements of the Animal Welfare Act, which states that programs of disease prevention and parasite control, euthanasia, and adequate veterinary care shall be established and maintained under the supervision of a veterinarian. Ideally the zoo and aquarium should be providing the best possible veterinary medical care for the animals in their collections. Many of these animals are rare and endangered and the institutions should endeavor both to provide for the long term health and well being of these animals and to advance the field of non-domestic animal medicine. It is hoped that this publication will aid in this process. 相似文献
338.
Ilona D. Bruins Slot Maria G. E. G. Bremer Ine van der Fels‐Klerx Rob J. Hamer 《Cereal Chemistry》2015,92(5):513-521
A wide variety of enzyme‐linked immunosorbent assays (ELISAs) are commercially available for gluten detection in food, including new formats and assays with antibodies against relevant gluten epitopes. Nevertheless, problems persist to accurately determine the gluten content of products. In this study, the performance of a set of 14 ELISA kits for gluten detection, representative of the current ELISA methods available on the market, was evaluated. These tests were used to determine gluten content in a series of relevant food matrices varying in complexity. Our results show that, currently, there is no single ELISA method that can accurately detect and quantify gluten in all different matrices. This includes the current type I method R5 as recommended by Codex Alimentarius. We conclude that further improvements are urgently needed and recommend focusing on competitive formats, improving extraction methods, and the detection of relevant gluten peptides (in order of priority). 相似文献