排序方式: 共有25条查询结果,搜索用时 140 毫秒
21.
Mariela Gómez-Romero Roberto Lindig-Cisneros Sebastiana Galindo-Vallejo 《Plant Ecology》2006,183(2):207-213
Plant establishment on sites affected by major volcanic disturbances is limited by several factors, such as lack of suitable
microsites for germination and establishment in sites affected by tephra from volcanic eruptions. Even after long periods
of time, tephra deposited over un-vegetated areas (agricultural fields and other barren areas) lack closed vegetation cover
and in many cases late successional species. To assess limiting factors for plant establishment, a field survey in a tephra
deposit from the Paricutin volcano eruption (19°30′42.4′′ N, 102°12′03.0′′) and greenhouse experiments were carried out. The
field survey determined the relationship between tephra depth and vegetation distribution. Greenhouse experiments determined
the effect of tephra depth on establishment and growth of two dominant species in the tephra deposit surveyed, Eupatorium glabratum and Lupinus elegans. Our results suggest that size and spatial distribution of vegetation patches is related to tephra depth in the field (77%
of the vegetation patches were on tephra 38.8 cm deep or less and only 2% on tephra of more than 46.8 cm). Under greenhouse
conditions, Eupatorium glabratum and Lupinus elegans height sharply decreased as depth of the tephra layer increased. Lupinus elegans plants growing in tephra less than 30 cm deep had a mean weight of 10.56 g (±0.53 g) compared with 3.11 g (±0.46 g) for plants
growing in tephra more than 30 cm deep. Our results suggest that tephra depth is a limiting factor for canopy development
in barren areas affected by tephra deposition. 相似文献
22.
Sebastiana Tola Daniela Manunta Monica Cocco Franco Turrini Angela M. Rocchigiani Graziano Idini Antonio Angioi Guido Leori 《FEMS microbiology letters》1997,154(2):355-362
We have analyzed antigenic variation of seven M. agalactiae wild strains using different sera from naturally infected sheep. Only 30 day sera recognized all surface proteins and inhibited the growth of mycoplasmas. Furthermore, we have observed that two strongly immunogenic proteins: 55 and 35 kDa were digested using 500 μg/ml of trypsin. These two bands are immunoprecipitated together with four other proteins but only the 35 kDa protein is recognized by eluted antibodies. 相似文献
23.
Giulia Francesca Cifuni Andrea Amici Michela Contò Paolo Viola Sebastiana Failla 《European Journal of Wildlife Research》2014,60(3):519-526
This study examines the influence of hunting methods on the colour and lipid oxidation state of meat from wild boar (Sus scrofa) and fallow deer (Dama dama). In addition, the feasibility of using visible reflectance spectra (360 to 740 nm) to predict the lipid oxidation of meat was evaluated. A total of 25 wild boars and 14 fallow deer were hunted with two different methods, dog-driven hunting (DH) and harvest culling (HC), that imply different animal stresses before shooting. Lipid oxidation increased in the meat from both species, which had been frozen for 3 months. The increase was higher in the DH group than the HC group (P?<?0.05). Our results confirm the importance of hunting stress on meat quality and lipid stability. The multivariate regression analysis showed a high correlation (R 2?=?0.968) between the predicted and measured thiobarbituric acid-reactive substances (TBARS) values, suggesting that visible spectroscopy should prove useful for predicting meat oxidation. 相似文献
24.
25.
Sebastiana Tola Graziano Idini Daniela Manunta Ida Casciano angela M. Rocchigiani Antonio Angioi Guido Leori 《FEMS microbiology letters》1996,143(2-3):259-265
Abstract We have analyzed 81 isolates of Mycoplasma agalactiae from four different regions of Italy between 1990 and 1995 in order to identify antigenic differences through SDS-PAGE and Western blotting and chromosomal DNA restriction endonuclease cleavage pattern differences. Antigenic variability in M. agalactiae isolates was investigated analyzing hydrophobic membrane protein fractions by immunoblotting using pooled sheep antiserum from naturally infected sheep. Large restriction fragments obtained cleaving genomic DNAs with Sma I, Nru I, Sal I, Xho I, Bss HII and Kpn I were analyzed by pulsed field gel electrophoresis. Genetic analysis indicates that isolates are all similar without intraspecific differences. This homogeneity was confirmed by immunoblotting: 80 and 50 kDa antigens are present in all strains analyzed. 相似文献