全文获取类型
收费全文 | 46篇 |
免费 | 2篇 |
出版年
2021年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2007年 | 1篇 |
2005年 | 1篇 |
2003年 | 1篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1971年 | 1篇 |
1959年 | 2篇 |
1958年 | 2篇 |
1955年 | 1篇 |
1954年 | 3篇 |
1953年 | 1篇 |
1952年 | 9篇 |
1951年 | 1篇 |
1950年 | 2篇 |
排序方式: 共有48条查询结果,搜索用时 15 毫秒
21.
NICOLA RICCI FABRIZIO ERRA ANTONIO RUSSO ROSALBA BANCHETTI Water-Air Interface 《The Journal of eukaryotic microbiology》1992,39(4):521-525
ABSTRACT Interference with the water-air interface, both direct (by contact with a flat, rigid surface) and indirect (by inducing a meniscus) caused the ciliated protozoa we investigated to actively collect in the water column or on the substrate directly under the area of altered surface tension. A crowding effect is observed in this "rest area" reaching plateau values within one hour after onset of the experiment. The simple experimental procedures described here induced analogous behaviour in both Paramecium caudatum (a swimmer) and Oxytricha bifaria (a crawler). The ciliates seem in this reaction to be seeking a refuge from vibrations transmitted by the free interface. Our discovery is discussed in its implications for the adaptive biology and ecology of these micro-organisms. 相似文献
22.
The origin of endemic South American canid fauna has been traditionally linked with the rise of the Isthmus of Panama, suggesting that diversification of the dog fauna on this continent occurred very rapidly. Nevertheless, despite its obvious biogeographic appeal, the tempo of Canid evolution in South America has never been studied thoroughly. This issue can be suitably tackled with the inference of a molecular timescale. In this study, using a relaxed molecular clock method, we estimated that the most recent common ancestor of South American canids lived around 4 Ma, whereas all other splits within the clade occurred after the rise of the Panamanian land bridge. We suggest that the early diversification of the ancestors of the two main lineages of South American canids may have occurred in North America, before the Great American Interchange. Moreover, a concatenated morphological and molecular analysis put some extinct canid species well within the South American radiation, and shows that the dental adaptations to hypercarnivory evolved only once in the South American clade. 相似文献
23.
24.
25.
Termite cohabitation: the relative effect of biotic and abiotic factors on mound biodiversity
下载免费PDF全文
![点击此处可从《Ecological Entomology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
ALESSANDRA MARINS DIOGO COSTA LAURA RUSSO COLIN CAMPBELL OG DESOUZA OTTAR N. BJØRNSTAD KATRIONA SHEA 《Ecological Entomology》2016,41(5):532-541
1. Termites are important ecosystem engineers that improve primary productivity in trees and animal diversity outside their mounds. However, their ecological relationship with the species nesting inside their mounds is poorly understood. 2. The presence of termite cohabitant colonies inside 145 Cornitermes cumulans mounds of known size and location was recorded. Using network‐theoretical methods in conjunction with a suite of statistical analyses, the relative influence of biotic and abiotic drivers of termite within‐mound diversity on the composition and species richness of the termite community was investigated, specifically builder presence and physical aspects of the mound. 3. We found that richness inside the mound increases with mound size, and the species similarity between mounds decreases with distance. The physical attributes (abiotic drivers) of termite mounds (size and relative distance to other mounds) are the strongest predictors of termite species richness and composition. The biotic driver (presence of a builder colony) has an important, though smaller, negative effect on within‐mound termite species richness. 4. The findings suggest that the termites' physical manipulation of their environment is an important driver of within‐mound community diversity. More generally, the approach taken here, using a combination of statistical and network‐theoretical methods, can be used to determine the relative importance of abiotic and biotic drivers of diversity in a wide range of communities of interacting species. 相似文献
26.
27.
28.
29.
CATHERINE CESA-LUNA JULIA-MARÍA ALATORRE-CRUZ RICARDO CARRE
O-L
PEZ VER
NICA QUINTERO-HERNNDEZ ANTONINO BAEZ 《Polish journal of microbiology》2021,70(2):143
The use of bacteriocins holds great promise in different areas such as health, food, nutrition, veterinary, nanotechnology, among others. Many research groups worldwide continue to advance the knowledge to unravel a novel range of therapeutic agents and food preservatives. This review addresses the advances of bacteriocins and their producer organisms as biocontrol agents for applications in the medical industry and agriculture. Furthermore, the bacteriocin mechanism of action and structural characteristics will be reviewed. Finally, the potential role of bacteriocins to modulate the signaling in host-associated microbial communities will be discussed. 相似文献
30.